找到用戶輸入的數中最大的數

題目：找到用戶輸入的數中最大的數，用戶一個一個輸入數，當輸入的數是0或者負數是輸出最大的非負數   

編譯器：vs2013

# define _CRT_SECURE_NO_WARNINGS
# include <stdio.h>
# include <stdlib.h>
int main()
{
float user_num; //用戶輸入的數
float compare_num = 0;//比較的數 切記初始化
while (1)
{
printf("Please input num:");
scanf("%f", &user_num);
if (user_num == 0 || user_num < 0)
{
printf("max is %f\n", compare_num);
break;
}
else if (user_num > compare_num)
compare_num = user_num;
}
system("pause");
return 0;
}