test66这个点爆int，要开long long

#include<cstdio>
int cnt=0;
long long a[100000001];
int main(){
   int n;
   scanf("%d",&n);
   int head=1,tail=n;
   for (int i=1;i<=n;i++)
     scanf("%d",&a[i]);
   while (head<tail){
   	   if (a[head]<a[tail])
		  {
		    a[head+1]+=a[head];
			head++; 
		    cnt++;
		   }
		else if (a[head]>a[tail])
		 {
		 	a[tail-1]+=a[tail];
		    tail--;
		    cnt++;
		 }
		else if (a[head]==a[tail])
		 {
		 	head++;
		 	tail--;		 
		 }  
   }
   printf("%d\n",cnt);
  return 0;
}