http://oj.acm.zstu.edu.cn/JudgeOnline/problem.php?cid=4034&pid=9

C语言版本一

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
 
int main(int argc, char *argv[]) {
    float const pi = acos(-1.0);
    int n;
    //scanf("%d",&n);
    n=100;
    while(n--){
    int a,b,c;
    float sa,sb,sc;
    scanf("%d %d %d",&a,&b,&c);
    sa=sqrt(3)/4 * a * a;
    sb=pi*b*b;
    sc=c*c;
    if(sa>sb&&sa>sc)printf("triangle\n");
    if(sb>sa&&sb>sc)printf("circle\n");
    if(sc>sb&&sc>sa)printf("square\n");
    }
 
      
    return 0;
}

C++版本一

#include<stdio.h>
#include<math.h>
#include<algorithm>
#include<string.h>
using namespace std;
 
int main(){
    double a,b,c,pi=acos(-1.0);
    while(~scanf("%lf%lf%lf",&a,&b,&c)){
        a=sqrt(3)/4*a*a;
        b=pi*b*b;
        c=c*c;
        if(c>b&&c>a)printf("square\n");
        if(b>c&&b>a)printf("circle\n");
        if(a>b&&a>c)printf("triangle\n");
    }
    return 0;
}