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Find the intersection of two Matrices
• Difficulty Level : Basic
• Last Updated : 30 Apr, 2021

Given two matrix A[][] and B[][] of same order m*n. The task is to find the intersection of both matrix as C, where:

• Cij = Aij if Aij = Bij
• C = “*”, otherwise.

Examples:

```Input :
A[N][N] = {{2, 4, 6, 8},
{1, 3, 5, 7},
{8, 6, 4, 2},
{7, 5, 3, 1}};

B[N][N] = {{0, 4, 3, 8},
{1, 3, 5, 7},
{8, 3, 6, 2},
{4, 5, 3, 4}};
Output :
* 4 * 8
1 3 5 7
8 * * 2
* 5 3 * ```

As intersection of two set is a set which includes common elements to both set, similarly intersection of two matrix will include only corresponding common element and place “*” at the position of rest unmatching elements.
For finding the intersection of both matrix simply iterate over their size and print * if element at particular position in both matrix are not equal else print the element.
Below is the implementation of the above approach:

## C++

 `// CPP program to find intersection``// of two matrices` `#include ``#define N 4``#define M 4` `using` `namespace` `std;` `// Function to print the resultant matrix``void` `printIntersection(``int` `A[][N], ``int` `B[][N])``{``    ``for` `(``int` `i = 0; i < M; i++) {``        ``for` `(``int` `j = 0; j < N; j++) {` `            ``// print element value for equal``            ``// elements else *``            ``if` `(A[i][j] == B[i][j])``                ``cout << A[i][j] << ``" "``;``            ``else``                ``cout << ``"* "``;``        ``}` `        ``cout << ``"\n"``;``    ``}``}` `// Driver Code``int` `main()``{``    ``int` `A[M][N] = { { 2, 4, 6, 8 },``                    ``{ 1, 3, 5, 7 },``                    ``{ 8, 6, 4, 2 },``                    ``{ 7, 5, 3, 1 } };``    ``int` `B[M][N] = { { 2, 3, 6, 8 },``                    ``{ 1, 3, 5, 2 },``                    ``{ 8, 1, 4, 2 },``                    ``{ 3, 5, 4, 1 } };` `    ``printIntersection(A, B);` `    ``return` `0;``}`

## Java

 `//  Java program to find intersection``// of two matrices` `import` `java.io.*;` `class` `GFG {``  ``static` `int` `N = ``4``;``static` `int` `M = ``4``;`   `// Function to print the resultant matrix``static` `void` `printIntersection(``int` `A[][], ``int` `B[][])``{``    ``for` `(``int` `i = ``0``; i < M; i++) {``        ``for` `(``int` `j = ``0``; j < N; j++) {` `            ``// print element value for equal``            ``// elements else *``            ``if` `(A[i][j] == B[i][j])``                ``System.out.print(A[i][j] +``" "``);``            ``else``                ``System.out.print( ``"* "``);``        ``}` `        ``System.out.println( ``" "``);``    ``}``}` `// Driver Code` `    ``public` `static` `void` `main (String[] args) {``           ``int` `A[][] = { { ``2``, ``4``, ``6``, ``8` `},``                    ``{ ``1``, ``3``, ``5``, ``7` `},``                    ``{ ``8``, ``6``, ``4``, ``2` `},``                    ``{ ``7``, ``5``, ``3``, ``1` `} };``    ``int` `B[][] = { { ``2``, ``3``, ``6``, ``8` `},``                    ``{ ``1``, ``3``, ``5``, ``2` `},``                    ``{ ``8``, ``1``, ``4``, ``2` `},``                    ``{ ``3``, ``5``, ``4``, ``1` `} };` `    ``printIntersection(A, B);` `    ``}``}``// This code is contributed by anuj_67..`

## Python3

 `# Python 3 program to find intersection``# of two matrices``N, M ``=` `4``, ``4` `# Function to print the resultant matrix``def` `printIntersection(A, B) :` `    ``for` `i ``in` `range``(M) :``        ``for` `j ``in` `range``(N) :` `            ``# print element value for equal``            ``# elements else *``            ``if` `(A[i][j] ``=``=` `B[i][j]) :``                ``print``(A[i][j], end ``=` `" "``)``            ``else` `:``                ``print``(``"* "``, end ``=` `" "``)``        ` `        ``print``()``        ` `# Driver Code``if` `__name__ ``=``=` `"__main__"` `:``    ` `    ``A ``=` `[ [``2``, ``4``, ``6``, ``8` `],``        ``[ ``1``, ``3``, ``5``, ``7` `],``        ``[ ``8``, ``6``, ``4``, ``2` `],``        ``[ ``7``, ``5``, ``3``, ``1` `] ]``        ` `    ``B ``=` `[ [ ``2``, ``3``, ``6``, ``8` `],``        ``[ ``1``, ``3``, ``5``, ``2` `],``        ``[ ``8``, ``1``, ``4``, ``2` `],``        ``[ ``3``, ``5``, ``4``, ``1` `] ]` `    ``printIntersection(A, B)` `# This code is contributed by Ryuga`

## C#

 `// C# program to find intersection``// of two matrices` `using` `System;` `class` `GFG {``static` `int` `N = 4;``static` `int` `M = 4;`   `// Function to print the resultant matrix``static` `void` `printIntersection(``int` `[,]A, ``int` `[,]B)``{``    ``for` `(``int` `i = 0; i < M; i++) {``        ``for` `(``int` `j = 0; j < N; j++) {` `            ``// print element value for equal``            ``// elements else *``            ``if` `(A[i,j] == B[i,j])``                ``Console.Write(A[i,j] +``" "``);``            ``else``                ``Console.Write( ``"* "``);``        ``}` `        ``Console.WriteLine( ``" "``);``    ``}``}` `// Driver Code` `    ``public` `static` `void` `Main () {``        ``int` `[,]A = { { 2, 4, 6, 8 },``                    ``{ 1, 3, 5, 7 },``                    ``{ 8, 6, 4, 2 },``                    ``{ 7, 5, 3, 1 } };``    ``int` `[,]B = { { 2, 3, 6, 8 },``                    ``{ 1, 3, 5, 2 },``                    ``{ 8, 1, 4, 2 },``                    ``{ 3, 5, 4, 1 } };` `    ``printIntersection(A, B);` `    ``}``}``// This code is contributed by inder_verma..`

## PHP

 ``

## Javascript

 ``
Output:
```2 * 6 8
1 3 5 *
8 * 4 2
* 5 * 1```

Time Complexity: O(M * N)

Auxiliary Space: O(1)

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