#include <stdio.h>
int main()
{
    int a;
    printf("please your score\n");
    scanf("%d",&a);
    if((a%4==0 )&&(a%100!=0));
   
        printf("%d is leap year\n",a);
   
    else
    {
        printf("the year isn ");
    }


    return 0;
}

if((a%4==0 )&&(a%100!=0));  多了个分号，细心点就好了

谢谢哥哥，粗心了