编译成功

foo.c: In function 'main':
foo.c:8:3: warning: format '%s' expects argument of type 'char ', but argument 2 has type 'char ()[20000]' [-Wformat=]
scanf("%s",&a);
^
测试数据 #0: Accepted, time = 0 ms, mem = 496 KiB, score = 20
测试数据 #1: Accepted, time = 0 ms, mem = 496 KiB, score = 20
测试数据 #2: Accepted, time = 0 ms, mem = 496 KiB, score = 20
测试数据 #3: Accepted, time = 0 ms, mem = 496 KiB, score = 20
测试数据 #4: Accepted, time = 0 ms, mem = 496 KiB, score = 20
Accepted, time = 0 ms, mem = 496 KiB, score = 100
代码
#include<stdio.h>
#include<string.h>

int main()
{
char a[20000]={0};
int n;
scanf("%s",&a);
n=a[strlen(a)-1]+a[strlen(a)-2]*10;
n%=4;
if(n==1||n==2) printf("1\n");
else printf("0\n");
return 0;
}