找到用户输入的数中最大的数

题目：找到用户输入的数中最大的数，用户一个一个输入数，当输入的数是0或者负数是输出最大的非负数   

编译器：vs2013

# define _CRT_SECURE_NO_WARNINGS
# include <stdio.h>
# include <stdlib.h>
int main()
{
float user_num; //用户输入的数
float compare_num = 0;//比较的数 切记初始化
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;
}