class Solution {
public:
    int timeDifference(pair<int, int> before, pair<int, int> after){
        unsigned diff = 0;
        if (after.first == before.first) diff = after.second - before.second;
        else {
            diff += after.second - before.second + 60;
            before.first++;
            diff += (after.first - before.first) * 60;
        }
        return diff;
    }
    int findMinDifference(vector<string>& timePoints) {
        int currDifference{0}, minDifference{1441};
        pair<int, int> before, after;
        sort(timePoints.begin(), timePoints.end());
        before = make_pair(stoi(timePoints[timePoints.size()-1].substr(0, 2)), stoi(timePoints[timePoints.size()-1].substr(3, 2)));
        after = make_pair(stoi(timePoints[0].substr(0, 2)) + 24, stoi(timePoints[0].substr(3, 2)));
        currDifference = timeDifference(before, after);
        minDifference = min(currDifference, minDifference);
        
        
        for (int i = 1; i < timePoints.size(); i++){
            
            before = make_pair(stoi(timePoints[i-1].substr(0, 2)), stoi(timePoints[i-1].substr(3, 2)));
            after = make_pair(stoi(timePoints[i].substr(0, 2)), stoi(timePoints[i].substr(3, 2)));
            currDifference = timeDifference(before, after);
            minDifference = min(currDifference, minDifference);
        }
        return minDifference;
    }
};