Merkkijono

#include  <iostream>

using namespace std;

bool include[1005];
int main() {
    for(int i = 0; i < 1000; i++) {
        include[i] = true;
    }
    string s;
    cin >> s;
    int maxIndex = s.length() - 1;
    for(int k = 0; k < maxIndex; k++) {
        for(int i = 0; i < maxIndex; i++) {
            bool deleted = false;
            if(!include[i]) {
                continue;
            }
            int j = i + 1;
            while(!include[j]) {
                j++;
                if(j > maxIndex) {
                    break;
                }
            }
            if(j > maxIndex) {
                break;
            }
            while(s.at(i) == s.at(j)) {
                include[i] = false;
                include[j] = false;
                deleted = true;
                j++;
                if(j > maxIndex) {
                    break;
                }
                while(!include[j]) {
                    j++;
                    if(j > maxIndex) {
                        break;
                    }
                }
                if(j > maxIndex) {
                    break;
                }
            }
            if(deleted) {
                break;
            }
        }
    }
    for(int i = 0; i <= maxIndex; i++) {
        if(include[i]) {
            cout << s.at(i);
        }
    }
    cout << "\n";
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED