Hi every body, my first post here 
I'm getting a WA response from the judge system for the problem code GERGOVIA
http://www.spoj.pl/problems/GERGOVIA
and here is my code:
#include <iostream>
#include <vector>
#include <utility>
#include <algorithm>
#include <math.h>
using namespace std;
int main() {
while (true) {
int n, units = 0;
cin >> n;
if (n == 0)
break;
// first: index, second: value
vector<pair<int, int> > sellers, consumers;
for (int i = 0; i < n; i++) {
int person;
cin >> person;
// Seller
if (person < 0) {
sellers.push_back(make_pair(i, -person));
bool stop = false;
int sellInd = sellers.size() - 1;
while (!stop && !consumers.empty()) {
int consInd = consumers.size() - 1;
if (sellers[sellInd].second < consumers[consInd].second) {
units += (sellers[sellInd].second * abs(
i - consumers[consInd].first));
consumers[consInd].second -= sellers[sellInd].second;
sellers.pop_back();
stop = true;
} else if (sellers[sellInd].second
> consumers[consInd].second) {
units += (consumers[consInd].second * abs(
i - consumers[consInd].first));
sellers[sellInd].second -= consumers[consInd].second;
consumers.pop_back();
} else {
units += (consumers[consInd].second * abs(
i - consumers[consInd].first));
consumers.pop_back();
sellers.pop_back();
stop = true;
}
}
}
// Consumer
else if (person > 0) {
consumers.push_back(make_pair(i, person));
bool stop = false;
int consInd = consumers.size() - 1;
while (!stop && !sellers.empty()) {
int sellInd = sellers.size() - 1;
if (sellers[sellInd].second < consumers[consInd].second) {
units += (sellers[sellInd].second * abs(
i - sellers[sellInd].first));
consumers[consInd].second -= sellers[sellInd].second;
sellers.pop_back();
} else if (sellers[sellInd].second
> consumers[consInd].second) {
units += (consumers[consInd].second * abs(
i - sellers[sellInd].first));
sellers[sellInd].second -= consumers[consInd].second;
consumers.pop_back();
stop = true;
} else {
units += (consumers[consInd].second * abs(
i - sellers[sellInd].first));
consumers.pop_back();
sellers.pop_back();
stop = true;
}
}
}
}
cout << units << endl;
}
return 0;
}
i wish if any one could provide me some test cases to know where exactly I'm wrong
