C++ customized comparison part 2

Part 1 can be found here.

For part 2, I am going to focus on using some real examples to show how to use customized comparison. Those examples will be added to this article gradually.

Vector

1710. Maximum Units on a Truck

class Solution {
public:
    int maximumUnits(vector<vector<int>>& a, int truckSize) {
        sort(a.begin(), a.end(), 
             [](const vector<int>& lhs, const vector<int>& rhs) {
            return lhs[1] > rhs[1];
        });
        int ret = 0, used = 0;
        for (int i = 0; i < a.size() && truckSize > 0; ++i) {
            used = min(truckSize, a[i][0]);
            ret += used*a[i][1];
            truckSize -= used;
        }
        return ret;
    }
};

Or we can use auto

class Solution {
public:
    int maximumUnits(vector<vector<int>>& a, int truckSize) {
        sort(a.begin(), a.end(), 
             [](const auto& lhs, const auto& rhs) {
            return lhs[1] > rhs[1];
        });
        int ret = 0, used = 0;
        for (int i = 0; i < a.size() && truckSize > 0; ++i) {
            used = min(truckSize, a[i][0]);
            ret += used*a[i][1];
            truckSize -= used;
        }
        return ret;
    }
};

Thanks for reading and hope it helps.