算法修炼之练气篇——练气四层

#include<stdio.h>intmain()
{
inta,b;
boolc;
scanf("%d",&a);
c=a;
b=c;
printf("%d",b);
return0;
}

#include<stdio.h>#include<stdbool.h>//这个头文件我也是第一次见intmain()
{
inta,b;
boolc;
scanf("%d",&a);
c=a;
b=c;
printf("%d",b);
return0;
}

#include<stdio.h>intmain()
{
charn;
scanf("%c",&n);
if(n%2==0)
    {
printf("NO");
    }
else    {
printf("YES");
    }
return0;    
}

#include<stdio.h>intmain()
{
intn;
scanf("%d",&n);
printf("%d",(n+1)*n/2);
return0;    
}

#include<stdio.h>#include<math.h>intmain()
{
doublep;
doubleS;
doublea,b,c;
doublex1,x2,x3,y1,y2,y3;
scanf("%lf %lf %lf %lf %lf %lf",&x1,&y1,&x2,&y2,&x3,&y3);
//两点之间距离公式a=(x1-x2)*(x1-x2)+(y1-y2)*(y1-y2);
a=sqrt(a);
b=(x1-x3)*(x1-x3)+(y1-y3)*(y1-y3);
b=sqrt(b);
c=(x2-x3)*(x2-x3)+(y2-y3)*(y2-y3);
c=sqrt(c);
//海伦公式，已知三角形三边求三角形面积//p=(a+b+c)/2，S=√[p(p-a)(p-b)(p-c)]p=(a+b+c)/2;
p=p*(p-a)*(p-b)*(p-c);
S=sqrt(p);
printf("%.2f",S);
return0;
}

#include<bits/stdc++.h>usingnamespacestd;
intmain()
{
strings;
while(getline(cin,s))//getline(cin,s)为什么用的时候老忘     {
if(s=="End of file")
        {
return0;
        }
for(inti=0;i<s.length();i++)//string长度获取是s.length()为什么用的时候老忘        {
if(s[i]>='a'&&s[i]<='z')
            {
s[i]=s[i]-32;
            }
        }
cout<<s<<endl;//直接输出就行了，为什么我当时用了一个循环//无语了！我以为是秒杀题，没想到好多常用的打的时候发现自己忘了，晕倒，，    }
return0;
}