求任意多个数的最大值，代码如下：
#include<stdio.h>
int main()
{
    int max(int a,int b);
    int a,c;
    printf("Please enter several positive integers:\n");
    for (c=0;c!='\n';)
    {
        a=c;
        scanf("%d",&c);
        c=max(a,c);
    }
    printf("The maximum is %d",c);
    return 0;
}
int max(int a,int b)
{
    int c;
    if (a>=b) c=a;
    else c=b;
    return c;
}
运行时永远无法结束程序。该怎么改才正确？