Range Addition II

You are given an m x n matrix M initialized with all 0's and an array of operations ops, where ops[i] = [ai, bi] means M[x][y] should be incremented by one for all 0 <= x < ai and 0 <= y < bi.

Count and return the number of maximum integers in the matrix after performing all the operations.

Example 1:

Input: m = 3, n = 3, ops = [[2,2],[3,3]]
Output: 4
Explanation: The maximum integer in M is 2, and there are four of it in M. So return 4.

Example 2:

Input: m = 3, n = 3, ops = [[2,2],[3,3],[3,3],[3,3],[2,2],[3,3],[3,3],[3,3],[2,2],[3,3],[3,3],[3,3]]
Output: 4

Example 3:

Input: m = 3, n = 3, ops = []
Output: 9

Solution: Track smallest

naive solution: fill all of matrix n * m

Improved solution: fill only top row and left column

Improved solution 2: track only smallest

func maxCount(m int, n int, ops [][]int) int {
    x := m
    y := n
    
    
    for _,pair := range ops {
        x = min(pair[0], x)
        y = min(pair[1], y)
    }
    return x * y
}

func min(i int, j int) int{
    if i >= j {
        return j
    } else {
        return i
    }
}

TC: O(N)

SC: O(1)