#include "stdio.h" 
#include "string.h" 
int main(void){ 
    char a[100],la[100],i; 
    printf("please enter 5 strings:"); 
    for(*la='\0',i=0;i<5;i++) 
        if(scanf("%s",a),strlen(a)>strlen(la))//总是保留较长的 
            strcpy(la,a); 
    printf("The longest string is: %s\n",la); 
   
    return 0; 
}