判断平年还是闰年

#include
int main()
{
int year;
int yushu;
scanf("%d",&year);
yushu=year%400;
if(yushu==0)
{
printf("是闰年\n");
return 0;
}
else
{
yushu=year%4;
if(yushu!=0)
{
printf("是平年\n");
return 0;
}
else
{
yushu=year%100;
if(yushu==0)
{
printf("是平年\n");
return 0;
}
else
{
printf("是闰年\n");
return 0;
}
return 0;
}
return 0;
}
return 0;
}