1380. Lucky number in matrix / 1672 Total assets of the richest customers

1380. The lucky number in the matrix 【 Simple questions 】【 A daily topic 】

Ideas ：

1. First find the minimum value of each line , Deposited in the collection list_r in , Set subscript corresponds to line number ; Then find out the maximum value of each column , Deposited in the collection list_c in , Set subscript corresponds to column number .
2. Traverse every element of the matrix , Use common for loop , Judge whether the current element is the minimum value of the current row and the maximum value of the current column , If both , Then add the current element to the collection ans in .
3. Finally back to ans that will do .

Code ：

class Solution {
    
    public List<Integer> luckyNumbers (int[][] matrix) {
    
        List<Integer> ans = new ArrayList<>();
        List<Integer> list_r = new ArrayList<>();
        List<Integer> list_c = new ArrayList<>();
        for (int[] row : matrix) {
    
            int min = Integer.MAX_VALUE;
            for (int col : row){
    
                min = Math.min(min,col);
            }
            list_r.add(min);
        }
        for (int i = 0; i < matrix[0].length; i++) {
    
            int max = 0;
            for (int[] row : matrix) {
    
                max = Math.max(max, row[i]);
            }
            list_c.add(max);
        }
        for (int i = 0; i < matrix.length; i++) {
    
            for (int j = 0; j < matrix[0].length; j++) {
    
                int cur = matrix[i][j];
                if (cur == list_r.get(i) && cur == list_c.get(j)){
    
                    ans.add(cur);
                }
            }
        }
        return ans;
    }
}

when ：

3ms, beat 55.52%.

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1672. Total assets of the richest clients 【 Simple questions 】

1. Define a int Type variable max Indicates the total assets of the richest customers .
2. Traverse every customer , Calculate its total assets sum, take max Updated to max and sum The maximum of .
3. After all customers are traversed, the current maximum value is returned max That is, the total assets of the richest customers .

Code ：

class Solution {
    
    public int maximumWealth(int[][] accounts) {
    
        int max = 0;
        for (int[] costumer : accounts){
    
            int sum = 0;
            for (int money : costumer){
    
                sum += money;
            }
            max = Math.max(max,sum);
        }
        return max;
    }
}

when ：

There is no official solution to this problem at present .