[GCJ] 2011 Qualification - C - Candy Splitting - http://kuoe0.ch/561/gcj-2011-qualification-c-candy-splitting/

C - Candy Splitting.cpp

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;
#define MAXN 1010

int num[ MAXN ];

int main() {
	freopen( "C.out", "w", stdout );
	int test;
	scanf( "%d", &test );

	for ( int t = 0; t < test; ++t ) {
		int n;
		scanf( "%d", &n );
		int sum = 0;
		for ( int i = 1; i <= n; ++i )
			scanf( "%d", &num[ i ] ), sum ^= num[ i ];
		
		if ( sum ) {
			printf( "Case #%d: NO\n", t + 1 );
			continue;
		}

		sort( num + 1, num + 1 + n );
		int now = 0, MAX = -1, current = 0;

		for ( int i = n; i > 1; --i ) {
			now ^= num[ i ], sum ^= num[ i ];
			current += num[ i ];
			if ( now == sum )
				MAX = max( MAX, current );
		}
		printf( "Case #%d: %d\n", t + 1, MAX );
	}
	return 0;
}