package math; import java.util.*; /** * Created by gouthamvidyapradhan on 09/10/2019 Given an m * n matrix M initialized with all 0's and * several update operations. * *

Operations are represented by a 2D array, and each operation is represented by an array with * two positive integers a and b, which means M[i][j] should be added by one for all 0 <= i < a and * 0 <= j < b. * *

You need to count and return the number of maximum integers in the matrix after performing all * the operations. * *

Example 1: Input: m = 3, n = 3 operations = [[2,2],[3,3]] Output: 4 Explanation: Initially, M * = [[0, 0, 0], [0, 0, 0], [0, 0, 0]] * *

After performing [2,2], M = [[1, 1, 0], [1, 1, 0], [0, 0, 0]] * *

After performing [3,3], M = [[2, 2, 1], [2, 2, 1], [1, 1, 1]] * *

So the maximum integer in M is 2, and there are four of it in M. So return 4. Note: The range * of m and n is [1,40000]. The range of a is [1,m], and the range of b is [1,n]. The range of * operations size won't exceed 10,000. * *

Solution: O(N) where N is the number of operations. For every operation, keep track of minimum * of each row and column and return the product of minR x minC */ public class RangeAdditionII { public static void main(String[] args) { // } public int maxCount(int m, int n, int[][] ops) { int minR = m; int minC = n; for (int[] v : ops) { minR = Math.min(minR, v[0]); minC = Math.min(minC, v[1]); } return minR * minC; } }