题解 | #三角形判断#

#include <stdio.h>

int main() {
    int a = 0;
    int b = 0;
    int c = 0;

    while (scanf("%d %d %d", &a, &b, &c) != EOF) {

        //将三边从小到大排序
        int tmp = 0;
        if (a > b) {
            tmp = a;
            a = b;
            b = tmp;
        }
        if (a > c) {
            tmp = a;
            a = c;
            c = tmp;
        }
        if (b > c) {
            tmp = b;
            b = c;
            c = tmp;
        }

        if (a + b > c) {//判断是否构成三角形
            if (a == b || b == c || a == c) {//判断是否等腰
                if (a == b && b == c)//判断是否等边
                    printf("Equilateral triangle!\n");
                else
                    printf("Isosceles triangle!\n");
            } 
            else
                printf("Ordinary triangle!\n");
        } 
        else
            printf("Not a triangle!\n");
        }
    return 0;
}