1 字符串最后一个单词的长度

#include <iostream>
using namespace std;
int main()
{
    char ch[128];
    while (cin.getline(ch, 128))
    {
        int len = 0;
        for (int i = 0; ch[i] != '\0'; i++)
        {
            if (ch[i] == ' ')
            {
                len = 0;
            }
            else
            {
                len++;
            }
        }
        cout<<len<<endl;
    }
}

2 合唱队

//动态规划，两头遍历
#include <iostream>
#include <vector>
using namespace std;
int main()
{
    int num;
    while (cin>>num)
    {
        vector<int> p(num);
        for (int i = 0; i < num; i++)
        {
            cin>>p[i];
        }
        vector<int> left(num, 1);
        vector<int> right(num, 1);
        for (int i = 1; i < num; i++)
        {
            for (int j = 0; j < i; j++)
            {
                if (p[i] > p[j] && left[j] + 1 > left[i])
                {
                    left[i] = left[j] + 1;
                }
            }
        }
        for (int i = num - 2; i >= 0; i--)
        {
            for (int j = num - 1; j > i; j--)
            {
                if (p[i] > p[j] && right[j] + 1 > right[i])
                {
                    right[i] = right[j] + 1;
                }
            }
        }
        int res = 0;
        for (int i = 0; i < num; i++)
        {
            res = max(res, left[i] + right[i] - 1);
        }
        cout<<num-res<<endl;
    }
}

3 挑7

//找出不大于n的数里面7的倍数以及某位数为7的数的个数
#include <iostream>
using namespace std;
bool fun(int n)
{
    while (n)
    {
        if (n % 10 == 7)
        {
            return true;
        }
        n /= 10;
    }
    return false;
}
int main()
{
    int n;
    while (cin>>n)
    {
        int res = 0;
        for (int i = 7; i <= n; i++)
        {
            if (i % 7 == 0 || fun(i))
            {
                res++;
            }
        }
        cout<<res<<endl;
    }
}

4 配置文件恢复

#include <iostream>
#include <cstring>
#include <string>
using namespace std;
string key1[6] = {"reset","reset","board","board","reboot","backplane"};
string key2[6] = {"","board","add","delet","backplane","abort"};
string result[6] = {"reset what","board fault","where to add","no board at all","impossible","install first"};
bool fun(string str1, string str2)
{
    bool b = true;
    if (str1.size() > str2.size())
    {
        return false;
    }
    for (int i = 0; i < str1.size(); i++)
    {
        if (str1[i] != str2[i])
        {
            b = false;
        }
    }
    return b;
}
int main()
{
    string str;
    while (getline(cin, str))
    {
        string first = "";
        string second = "";
        int blank = 0;
        for (int i = 0; i < str.size(); i++)
        {
            if (str[i] == ' ')
            {
                blank++;
            }
            else if (blank == 0)
            {
                first += str[i];
            }
            else
            {
                second += str[i];
            }
        }
        int res = -1;
        if (first == "") //无关键字
        {
            //res = -1;
            cout<<endl;
            continue;
        }
        else if (second == "") //一个关键字
        {
            if (fun(first, key1[0]))
            {
                res = 0;
            }
        }
        else //两个关键字
        {
            int cnt = 0;
            for (int i = 1; i < 6; i++)
            {
                if (fun(first, key1[i]) && fun(second, key2[i]))
                {
                    cnt++;
                    res = i;
                }
            }
            if (cnt != 1)
            {
                res = -1;
            }
        }
        if (res == -1)
        {
            cout<<"unkown command"<<endl;
        }
        else
        {
            cout<<result[res].c_str()<<endl;
        }
    }
}

5 购物单

#include <iostream>
#include <vector>
using namespace std;
int main()
{
    int total;
    int cnt;
    while (cin>>total>>cnt)
    {
        vector<vector<int>> goods(cnt + 1, vector<int>(3, 0));
        for (int i = 1; i <= cnt; i++)
        {
            cin>>goods[i][0]>>goods[i][1]>>goods[i][2];
        }
        vector<int> res(total + 1, 0);
        for (int i = 1; i <= cnt; i++)
        {
            for (int j = total; j >= 1; j--)
            {
                int temp = goods[i][0];
                int zhujian = goods[i][2];
                while (zhujian != 0)
                {
                    temp += goods[zhujian][0];
                    zhujian = goods[zhujian][2];
                }
                if (j >= temp)
                {
                    res[j] = max(res[j], res[j - temp] + goods[i][0] * goods[i][1]);
                }
            }
        }
        cout<<res[total]<<endl;
    }
}

6坐标移动

#include <iostream>
#include <string>
#include <vector>
using namespace std;
enum Direction { A = 'A', S = 'S', W = 'W', D = 'D'};
void move(int &x, int &y, Direction dir, int dist)
{
    switch (dir)
    {
    case 'A':
        x -= dist;
        break;
    case 'D':
        x += dist;
        break;
    case 'W':
        y += dist;
        break;
    case 'S':
        y -= dist;
        break;
    }
}
void transfer(string str, int& x, int& y)
{
    Direction dir;
    int dist;
    if (str[0] == 'A' || str[0] == 'D' || str[0] == 'W' || str[0] == 'S')
    {
        dir = (Direction)str[0];
        if (str[1] >= '0' && str[1] <= '9')
        {
            dist = str[1] - '0';
            if (str.size() == 3)
            {
                if (str[2] >= '0' && str[2] <= '9')
                {
                    dist = dist * 10 + str[2] - '0';
                }
                else
                {
                    return;
                }
            }
            move(x, y, dir, dist);
        }
    }
}
int main()
{
    string str;
    getline(cin, str);
    int x = 0;
    int y = 0;
    string temp = "";
    for (int i = 0; i < str.size(); i++)
    {
        if (str[i] != ';')
        {
            temp += str[i];
        }
        else
        {
            if (temp.size() == 3 || temp.size() == 2)
            {
                transfer(temp, x, y);
            }
            temp = "";
        }
    }
    cout<<x<<","<<y;
}

7 识别有效的IP地址和掩码并进行分类统计

#include <iostream>
#include <string>
#include <cstring>
#include <vector>
#include <cstdio>
using namespace std;
bool checkip(vector<int> num)
{
    for (int i = 0; i < 4; i++)
    {
        if (num[i] < 0 || num[i] > 255)
        {
            return false;
        }
    }
    return true;
}
bool checkmark(vector<int> num)
{
    int sum = num[0] << 24 | num[1] << 16 | num[2] << 8 | num[3];
    bool b = false;
    for (int i = 0; i < 32; i++)
    {
        if ((sum & 1 << i) == 0)
        {
            if (b == true)
            {
                return false;
            }
        }
        else
        {
            b = true;
        }
    }
    return true;
}
int str2num(string str)
{
    int res = 0;
    for (int i = 0; i < str.size(); i++)
    {
        res = res * 10 + str[i] - '0';
    }
    return res;
}
vector<int> seperate(string str)
{
    vector<int> ss;
    int i = 0;
    int j;
    string temp;
    while ((j = str.find('.', i)) != string::npos)
    {
        temp = str.substr(i, j - i);
        if (temp.size() != 0)
        {
            ss.push_back(str2num(temp));
        }
        else
        {
            ss.push_back(-1);
        }
        i = j + 1;
    }
    temp = str.substr(i);
    if (temp.size() != 0)
    {
        ss.push_back(str2num(temp));
    }
    else
    {
        ss.push_back(-1);
    }
    return ss;
}
int main()
{
    string str;
    int cnt[7] = {0};
    while (getline(cin, str))
    {
        if (str.size() == 0)
        {
            break;
        }
        int i = 0;
        int j;
        j = str.find('~');
        string strIp = str.substr(0, j);
        string strMark = str.substr(j + 1);
        vector<int> ip = seperate(strIp);
        vector<int> mark = seperate(strMark);
        if (checkip(ip) && checkmark(mark))
        {
            if (ip[0] >= 1 && ip[0] <= 126)
            {
                cnt[0]++;
            }
            else if (ip[0] >= 128 && ip[0] <= 191)
            {
                cnt[1]++;
            }
            else if (ip[0] >= 192 && ip[0] <= 223)
            {
                cnt[2]++;
            }
            else if (ip[0] >= 224 && ip[0] <= 239)
            {
                cnt[3]++;
            }
            else
            {
                cnt[4]++;
            }
            if ((ip[0] == 10) || (ip[0] == 172 && ip[1] >= 16 && ip[1] <= 31)
                || (ip[0] == 192 && ip[1] == 168))
            {
                cnt[6]++;
            }
        }
        else
        {
            cnt[5]++;
        }
    }
    for (int i = 0; i < 7; i++)
    {
        cout<<cnt[i]<<" ";
    }
}

8 字符逆序

#include <iostream>
#include <string>
#include <algorithm>
using namespace std;

int main()
{
    string str;
    while (getline(cin, str))
    {
        reverse(str.begin(), str.end());
        cout<<str.c_str()<<endl;
    }
    return 0;
}

9 公共字串计算

//忽略大小写。还以为是字符串有空格，导致错了两次
#include <iostream>
#include <cstring>
#include <vector>
#include <cmath>
using namespace std;

int getCommonStrLength(char * str1, char * str2)
{
    int len1 = strlen(str1);
    int len2 = strlen(str2);
    vector<vector<int>> dp(len1 + 1, vector<int>(len2 + 1, 0));
    int res = 0;
    for (int i = 1; i <= len1; i++)
    {
        for (int j = 1; j <= len2; j++)
        {
            if (str1[i - 1] == str2[j - 1] || abs(str1[i - 1] - str2[j - 1]) == 32)
            {
                dp[i][j] = dp[i - 1][j - 1] + 1;
                res = max(res, dp[i][j]);
            }
        }
    }

    return res;
}

int main()
{
    char str1[100];
    char str2[100];
    while (cin>>str1>>str2)
    {
        cout<<getCommonStrLength(str1, str2)<<endl;
    }
    return 0;
}

10 统计大写字母个数

#include <iostream>
#include <string>
using namespace std;

int CalcCapital(string str)
{
    int cnt = 0;
    for (int i = 0; i < str.size(); i++)
    {
        if (str[i] >= 'A' && str[i] <= 'Z')
        {
            cnt++;
        }
    }

    return cnt;
}

int main()
{
    string str;
    while (getline(cin, str))
    {
        cout<<CalcCapital(str)<<endl;
    }
    return 0;
}

11 字符串反转

#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main()
{
    string str;
    while (getline(cin, str))
    {
        reverse(str.begin(), str.end());
        cout<<str.c_str()<<endl;
    }
    return 0;
}

12 找出字符串中第一个只出现一次的字符

#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
bool FindChar(char* str, char* c)
{
    int ch[128] = {0};
    char *p = str;
    while (*p != '\0')
    {
        ch[*p++]++;
    }
    p = str;
    while (*p != '\0')
    {
        if (ch[*p] == 1)
        {
            *c = *p;
            return true;
        }
        p++;
    }
    *c = '.';
    return false;
}
int main()
{
    char str[100];
    while (cin.getline(str, 100))
    {
        char ch;
        FindChar(str, &ch);
        cout<<ch<<endl;
    }
    return 0;
}

13 计算字符个数

#include <iostream>
#include <cstdio>
#include <string>
using namespace std;
int main()
{
    string str;
    while (getline(cin, str))
    {
        string temp;
        getline(cin, temp);
        char ch = temp[0];
        int cnt = 0;
        for (int i = 0; i < str.size(); i++)
        {
            if (str[i] == ch)
            {
                cnt++;
            }
        }
        cout<<cnt<<endl;
    }
    return 0;
}

14 字符串加解密

#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
using namespace std;
void Encrypt(char aucPassword[], char aucResult[])
{
    for (int i = 0; i < strlen(aucPassword); i++)
    {
        if (aucPassword[i] >= 'a' && aucPassword[i] < 'z')
        {
            aucResult[i] = aucPassword[i] - 31;
        }
        else if (aucPassword[i] >= 'A' && aucPassword[i] < 'Z')
        {
            aucResult[i] = aucPassword[i] + 33;
        }
        else if (aucPassword[i] >= '0' && aucPassword[i] < '9')
        {
            aucResult[i] = aucPassword[i] + 1;
        }
        else if (aucPassword[i] == 'Z')
        {
            aucResult[i] = 'a';
        }
        else if (aucPassword[i] == 'z')
        {
            aucResult[i] = 'A';
        }
        else if (aucPassword[i] == '9')
        {
            aucResult[i] = '0';
        }
    }
}
void unEncrypt(char result[], char password[])
{
    for (int i = 0; i < strlen(result); i++)
    {
        if (result[i] >= 'a' && result[i] < 'z')
        {
            password[i] = result[i] - 33;
        }
        else if (result[i] >= 'A' && result[i] < 'Z')
        {
            password[i] = result[i] + 31;
        }
        else if (result[i] >= '0' && result[i] < '9')
        {
            password[i] = result[i] - 1;
        }
        else if (result[i] == 'A')
        {
            password[i] = 'z';
        }
        else if (result[i] == 'a')
        {
            password[i] = 'Z';
        }
        else if (result[i] == '0')
        {
            password[i] = '9';
        }
    }
}
int main()
{
    char str1[100] = {0};
    char str2[100] = {0};
    cin.getline(str1, 100);
    Encrypt(str1, str2);
    cout<<str2<<endl;
    cin.getline(str1, 100);
    memset(str2, 0, strlen(str1));
    unEncrypt(str1, str2);
    cout<<str2<<endl;
    return 0;
}

15 蛇形矩阵

样例输入
4
样例输出
1 3 6 10
2 5 9
4 8
7

#include <iostream>
#include <vector>
using namespace std;
int main()
{
    int n;
    cin>>n;
    vector<vector<int>> num(n, vector<int>(n, 0));
    int p = 1;
    for (int i = 0; i < n; i++)
    {
        for (int j = i, k = 0; j >= 0 && k <= i; j--, k++)
        {
            num[j][k] = p++;
        }
    }
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n - i; j++)
        {
            cout<<num[i][j];
            if (j != n - i - 1)
            {
                cout<<" ";
            }
        }
        cout<<endl;
    }
    return 0;
}

16 字符串加密

#include <iostream>
#include <cstring>
#include <vector>
using namespace std;
int main()
{
    char key[100];
    char str[100];
    while (cin.getline(key, 100))
    {
        cin.getline(str, 100);
        char cnt[26] = {0};
        char hash[26];
        int index = 0;
        for (int i = 0; i < strlen(key); i++)
        {
            if (key[i] >= 'a')
            {
                key[i] -= 32;
            }
            if (cnt[key[i] - 'A'] == 0)
            {
                cnt[key[i] - 'A']++;
                hash[index++] = key[i];
            }
        }
        for (char ch = 'A'; ch <= 'Z'; ch++)
        {
            if (cnt[ch - 'A'] == 0)
            {
                hash[index++] = ch;
            }
        }
        for (int i = 0; i < strlen(str); i++)
        {
            if (str[i] == ' ')
            {
                continue;
            }
            bool flag = false;
            if (str[i] >= 'a')
            {
                str[i] -= 32;
                flag = true;
            }
            str[i] = hash[str[i] - 'A'];
            if (flag)
            {
                str[i] += 32;
            }
        }
        cout<<str<<endl;
    }
}

17 称砝码

#include <iostream>
#include <vector>
using namespace std;
int main()
{
    int n;
    while (cin>>n)
    {
        vector<int> fama(n, 0);
        vector<int> num(n, 0);
        int total = 0;
        for (int i = 0; i < n; i++)
        {
            cin>>fama[i];
        }
        for (int i = 0; i < n; i++)
        {
            cin>>num[i];
            total += fama[i] * num[i];
        }
        vector<bool> b(total + 1, false);
        b[0] = true;
        for (int i = 0; i < n; i++)
        {
            for (int j = 0; j < num[i]; j++)
            {
                for (int k = total; k >= fama[i]; k--)
                {
                    b[k] = b[k] || b[k - fama[i]];
                }
            }
        }
        int res = 0;
        for (int i = 0; i <= total; i++)
        {
            if (b[i])
            {
                res++;
            }
        }
        cout<<res<<endl;
    }
    return 0;
}
/*
6
1 2 3 5 10 20
1 2 2 0 0 1
ans:24
*/

18 iNOC产品部-杨辉三角的变形

#include <iostream>
#include <vector>
using namespace std;
int main()
{
    int n;
    cin>>n;
    vector<vector<int>> num(n, vector<int>(2 * n - 1, 0));
    num[0][n - 1] = 1;
    for (int i = 1; i < n; i++)
    {
        for (int j = n - 1 - i; j <= n - 1 + i; j++)
        {
            int temp = 0;
            if (j - 1 >= 0)
            {
                temp += num[i - 1][j - 1];
            }
            if (j + 1 < 2 * n - 1)
            {
                temp += num[i - 1][j + 1];
            }
            temp += num[i - 1][j];
            num[i][j] = temp;
        }
    }
    int index = -1;
    for (int i = 0; i < 2 * n - 1; i++)
    {
        if (num[n - 1][i] % 2 == 0)
        {
            index = i + 1;
            break;
        }
    }
    cout<<index<<endl;
    return 0;
}

19 查找组成一个偶数最接近的两个素数

#include <iostream>
#include <cmath>
using namespace std;
bool isPrime(int n)
{
    for (int i = 2; i <= n / 2; i++)
    {
        if (n % i == 0)
        {
            return false;
        }
    }
    return true;
}
int main()
{
    int n;
    while (cin>>n)
    {
        int a, b;
        int diff = n;
        for (int i = 3; i < n; i++)
        {
            if (isPrime(i) && isPrime(n - i))
            {
                if (abs(n - 2 * i) < diff)
                {
                    a = i;
                    b = n - i;
                    diff = abs(n - 2 * i);
                }
            }
        }
        cout<<a<<endl<<b<<endl;
    }
    return 0;
}

20 放苹果

#include <iostream>
#include <cmath>
using namespace std;

int fun(int m, int n)
{
    if (m == 0 || n == 1)
    {
        return 1;
    }
    else if (m < n)
    {
        return fun(m, m);
    }
    else
    {
        return fun(m, n - 1) + fun(m - n, n);
    }
}

int main()
{
    int m, n;
    while (cin>>m>>n)
    {
        cout<<fun(m, n)<<endl;
    }
    return 0;
}