Maximum and Minimum in a square matrix in C++

Problem statement

Given a square matrix of order n*n, find the maximum and minimum from the matrix

Example

If given matrix is −

{{15, 17, 19}, {5, 1, 7}, {14, 5, 16}} then Minimum number is 1 and maximum number is 19

Algorithm

• Select two elements from the matrix one from the start of a row of the matrix another from the end of the same row of the matrix
• Compare them and next compare smaller of them to the minimum of the matrix and larger of them to the maximum of the matrix.
• We can see that for two elements we need 3 compare so for traversing whole of the matrix we need total of 3/2n² comparisons

Example

Let us now see an example −

#include <bits/stdc++.h> #define MAX 200 using namespace std; void getMinMax(int matrix[MAX][MAX], int n) {    int min = INT_MAX;    int max = INT_MIN;    for (int i = 0; i < n; ++i) {       for (int j = 0; j <= n / 2; ++j){          if (matrix[i][j] > matri[i][n - j - 1]) {             if (min > matrixi][n - j - 1]) {                min = marix[i][n - j -1];             }             if (max < matrixi][j]) {                max = marix[i][j];             }          } else {             if (min > matrixi][j]) {                min = marix[i][j];             }             if (max < matrixi][n - j - 1]) {                max = marix[i][n - j - 1];             }          }       }    }    cout << "Maximum = " << max << ", Minimu = " << min << endl; } int main() {    int matrix[MAX][MAX] = { {15, 17, 19}, {5, 1, 7}, {14, 5, 16} };    getMinMax(matrix, 3);    return 0; }

Output

Maximum = 19, Minimum = 1