zoj 1402 Magnificent Meatballs

#include "iostream"
#include "memory.h"
using namespace std;

int meatballs[40];

int main()
{
	int guestnum, i, j, sum1, sum2;
	while (cin >> guestnum && guestnum)
	{
		memset(meatballs, 0, sizeof(meatballs));
		sum1 = sum2 = 0;
		for (i = 0; i < guestnum; i++)
			cin >> meatballs[i];
		sum1 += meatballs[0];
		sum2 += meatballs[guestnum-1];
		for (i = 1, j = guestnum-2; ;)
		{
			if (i > j)  break;//就是由于这个条件的位置没有放对，WA了几次！考虑不够周全！
			if (sum1 > sum2)
			{
				sum2 += meatballs[j];
				j = j -1;
			}
			else 
			{
				sum1 += meatballs[i];
				i = i + 1;
			}
		}
		if (sum1 == sum2)
			cout << "Sam stops at position " << i << " and Ella stops at position " << i + 1<< "." << endl;
		else
			cout << "No equal partitioning." << endl;
	}
}