Leetcode Contest Problems

Leetcode Weekly Contest 387

3069. Distribute Elements Into Two Arrays I

3070. Count Submatrices with Top-Left Element and Sum Less Than k

This is a dynamic programming problem

3071.Minimum Operations to write `Y` on grid

We can clearly see via the constraints that is is a backtracking problem

3072. Distribute Elements Into Two Arrays II

The problem is a application problem of lower and upper bound :

Notes

1. For set iterators arithmetic operations dont work like they do for array iterators ex. the operator - is not defined for the iterators of std::sets (bidirectional iterators) while it's defined for the arrays iterators (random access iterators).

   Instead, you can use std::distance(), as follows

    int main()
    {
        set<int> set {1, 2, 4, 5, 6};
        int number = 3;
        int lbIdx=distance(set.begin(), set.lower_bound(number)) ;
        cout<<"lower bound Index"<< lbIdx <<endl;
    }