# 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:**![](https://assets.leetcode.com/uploads/2020/10/02/ex1.jpg)

```
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

```go
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)
