UVa 562 - Dividing coins

#include <cstdio>
#include <iostream>
#include <string>
#include <cstring>
#include <algorithm>
const int MAXN = 110;

using namespace std;

int A[MAXN], sum, Case, num;
bool opt[MAXN * 500];

int main ( ) {
cin >> Case;
while ( Case-- ) {

memset ( opt, false, sizeof ( opt ) );
opt[0] = true;
sum = 0;

cin >> num;

for ( int i = 0; i < num; cin >> A[i], sum += A[i], ++i ) ;

for ( int i = 0; i < num; ++i )
for ( int j = sum; j >= A[i]; --j )
if ( opt[j - A[i]] ) opt[j] = true;

int mid;
for ( int i = sum / 2; i >= 0; --i )
if ( opt[i] ) {
mid = i;
break;
}

cout <<  ( sum - 2 * mid ) << endl;

}
return 0;
}