Build Failures

• Time : O(nlogm)
• Space : O(1)

int buildFailures(vector<vector<bool>> buildRuns) {
    int res = 0, count = 0, n = buildRuns.size();
    double rate = 1.0;
    for(auto& runs : buildRuns) {
        int success = rend(runs) - upper_bound(rbegin(runs), rend(runs), false);
        double cur = 1.0 * success / runs.size();
        if(cur < rate) {
            res = max(res, ++count);
        } else {
            count = 1;
        }
        rate = cur;
    }
    return res <= 1 ? -1 : res;
}