QUESTION:
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.
EXPLANATION:
其实倒是很容易想到的,2*2其实就就是这样,然后再3*3,这样的操作其实只有2*2的格子是进行过两次操作的。那么这个问题就变成了,哪些格子是进行过最多次的加法操作。那么问题就很简单了,就是求行和列的最小值,这个最小值就是经过+1次数最多的数了。
1.求出行的最小值
2.求出列的最小值
3.进行乘法运算,算出总个数。
SOLUTION:
public class Solution {
public int maxCount(int m, int n, int[][] ops) {
int row = Integer.MAX_VALUE;int colum = Integer.MAX_VALUE;
for(int i= 0;i<ops.length;i++){
row = Math.min(ops[i][0],row);
colum = Math.min(ops[i][1],colum);
}
row = Math.min(m,row);
colum = Math.min(n,colum);
return row*colum;
}
}