13. Roman to Integer
Problem's Link
----------------------------------------------------------------------------
Mean:
给你一个字符串,代表罗马数字,将其转换为int型数字.
analyse:
略
Time complexity: O(N)
view code
/**
* -----------------------------------------------------------------
* Copyright (c) 2016 crazyacking.All rights reserved.
* -----------------------------------------------------------------
* Author: crazyacking
* Date : 2016-02-16-12.06
*/
#include <queue>
#include <cstdio>
#include <set>
#include <string>
#include <stack>
#include <cmath>
#include <climits>
#include <map>
#include <cstdlib>
#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
#include <bits/stdc++.h>
using namespace std;
typedef long long( LL);
typedef unsigned long long( ULL);
const double eps( 1e-8);
class Solution
{
public :
int romanToInt( string s)
{
unordered_map < char , int > T =
{
{ 'I' , 1 },
{ 'V' , 5 },
{ 'X' , 10 },
{ 'L' , 50 },
{ 'C' , 100 },
{ 'D' , 500 },
{ 'M' , 1000 }
};
int sum = T [s . back ()];
for ( int i = s . length() - 2; i >= 0; -- i)
{
if ( T [s [ i ]] < T [s [ i + 1 ]])
sum -= T [s [ i ]];
else
sum += T [s [ i ]];
}
return sum;
}
};
int main()
{
Solution solution;
string s;
while( cin >>s)
{
cout << solution . romanToInt(s) << endl;
}
return 0;
}
* -----------------------------------------------------------------
* Copyright (c) 2016 crazyacking.All rights reserved.
* -----------------------------------------------------------------
* Author: crazyacking
* Date : 2016-02-16-12.06
*/
#include <queue>
#include <cstdio>
#include <set>
#include <string>
#include <stack>
#include <cmath>
#include <climits>
#include <map>
#include <cstdlib>
#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
#include <bits/stdc++.h>
using namespace std;
typedef long long( LL);
typedef unsigned long long( ULL);
const double eps( 1e-8);
class Solution
{
public :
int romanToInt( string s)
{
unordered_map < char , int > T =
{
{ 'I' , 1 },
{ 'V' , 5 },
{ 'X' , 10 },
{ 'L' , 50 },
{ 'C' , 100 },
{ 'D' , 500 },
{ 'M' , 1000 }
};
int sum = T [s . back ()];
for ( int i = s . length() - 2; i >= 0; -- i)
{
if ( T [s [ i ]] < T [s [ i + 1 ]])
sum -= T [s [ i ]];
else
sum += T [s [ i ]];
}
return sum;
}
};
int main()
{
Solution solution;
string s;
while( cin >>s)
{
cout << solution . romanToInt(s) << endl;
}
return 0;
}