根据三边长度判断三角形的形状 c语言

// 测试用例:
//          直角三角形:3 4 5
//          钝角三角形:3 5 7
//          锐角三角形:6 6 6
#include <stdio.h>
#include <stdlib.h>

// test if the three number is a triangle
 int isTriangle(int a, int b, int c)
 {
    if ((a > 0) && (b > 0) && (c > 0)
        && (a < b + c) && (b < a + c) && (c < a + b))
        return 1;
    else
        return 0;
 }

// output the triangle
void judge(int max, int a, int b)
{
    if (max * max == (a * a + b * b))
    {
        printf("直角三角形\n");
    }
    else
    {
        // 根据余弦定理来判定
        if (a * a + b * b - max * max > 0)
        {
            printf("锐角三角形\n");
        }
        else if (a * a + b * b - max * max < 0)
        {
            printf("钝角三角形\n");
        }
    }
}


int main()
{
    int a, b, c;

    printf("Enter three number to test if the three numbers can be made a triangle\n");
    scanf("%d" , &a);
    scanf("%d", &b);
    scanf("%d", &c);

    if(isTriangle(a, b, c))
    {
        // a >= b and c
        if ( (a >= b) && (a >= c) )
        {
            judge(a, b, c);
        }
        // b >=  a and c
        else if ( (b >= a) && (b >= c) )
        {
            judge(b, a, c);
        }
        // c >= a and b
        else if( (c >= a) && (c >= b) )
        {
            judge(c, a, b);
        }
    }

    return 0;
}

posted @ 2010-11-17 19:48  qiang.xu  阅读(6818)  评论(0编辑  收藏  举报