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Check if all enemies are killed with bombs placed in a matrix
• Difficulty Level : Basic
• Last Updated : 03 Feb, 2021

Given a Character matrix as input, the task is to check whether all the enemies are killed or not based on below conditions:

1. The matrix can contain 3 characters
X –> Denotes the War area.
B –> Denotes the bomb.
E –> Denotes the Enemies.
2. Bomb ‘B’ can blast in only horizontal and vertical directions from one end to another.
3. If all enemies are killed by the present bombs, print Yes, else print No

Examples:

```Input: matrix =
XXEX
XBXX
XEXX
XXBX
Output: Yes

Input: matrix =
XXEX
XBXX
XEXX
XXXX
Output: No```

Approach: The given problem can be solved by the following approach:

1. Get the character Matrix
2. Traverse to find all bomb indices in the matrix
3. For each bomb found, see if any enemy is present in its vertical or horizontal direction. If present kill that enemy, i.e. change E to X
4. After all traversals, check if any enemy is present in the matrix or not.
5. Print Yes if all enemies are killed, else print No.

Implementation:

## C++

 `// C++ program to kill all enemies` `#include ``using` `namespace` `std;` `// Function to find Enemies killed or not``int` `Kill_Enemy(string s[], ``int` `row, ``int` `col)``{` `    ``int` `i, j, x, y;` `    ``// Loop to evaluate the Bomb``    ``for` `(i = 0; i < row; i++) {``        ``for` `(j = 0; j < col; j++) {` `            ``// Check if this index is a bomb``            ``if` `(s[i][j] == ``'B'``) {` `                ``// Kill all enemies``                ``// in horizontal direction``                ``for` `(x = 0; x < row; x++) {``                    ``if` `(s[x][j] != ``'B'``)``                        ``s[x][j] = ``'X'``;``                ``}` `                ``// Kill all enemies``                ``// in vertical direction``                ``for` `(y = 0; y < col; y++) {``                    ``if` `(s[i][y] != ``'B'``)``                        ``s[i][y] = ``'X'``;``                ``}``            ``}``        ``}``    ``}``    ``// All bombs have been found` `    ``// Check if any enemy is still present``    ``for` `(i = 0; i < row; i++) {``        ``for` `(j = 0; j < col; j++) {` `            ``if` `(s[i][j] == ``'E'``)` `                ``// Since an enemy is present``                ``// Return 0 denoting No as output``                ``return` `0;``        ``}``    ``}` `    ``// Since all enemies are killed``    ``// Return 1 denoting Yes as output``    ``return` `1;``}` `// Driver Code``int` `main(``int` `argc, ``char``** argv)``{``    ``// Get the input matrix``    ``string s[] = { ``"XXEX"``,``                   ``"XBXX"``,``                   ``"XEXX"``,``                   ``"XXBX"` `};` `    ``// Calculate Rows and columns of the string``    ``int` `row = ``sizeof``(s) / ``sizeof``(s[0]),``        ``col = s[0].length();` `    ``// Check if all enemies will be killed or not``    ``if` `(Kill_Enemy(s, row, col) == 1)``        ``cout << ``"Yes"``;``    ``else``        ``cout << ``"No"``;` `    ``return` `0;``}`

## Java

 `// Java program to kill all enemies``class` `GFG``{` `// Function to find Enemies killed or not``static` `int` `Kill_Enemy(``char` `[][]s, ``int` `row, ``int` `col)``{` `    ``int` `i, j, x, y;` `    ``// Loop to evaluate the Bomb``    ``for` `(i = ``0``; i < row; i++)``    ``{``        ``for` `(j = ``0``; j < col; j++)``        ``{` `            ``// Check if this index is a bomb``            ``if` `(s[i][j] == ``'B'``)``            ``{` `                ``// Kill all enemies``                ``// in horizontal direction``                ``for` `(x = ``0``; x < row; x++)``                ``{``                    ``if` `(s[x][j] != ``'B'``)``                        ``s[x][j] = ``'X'``;``                ``}` `                ``// Kill all enemies``                ``// in vertical direction``                ``for` `(y = ``0``; y < col; y++)``                ``{``                    ``if` `(s[i][y] != ``'B'``)``                        ``s[i][y] = ``'X'``;``                ``}``            ``}``        ``}``    ``}``    ` `    ``// All bombs have been found` `    ``// Check if any enemy is still present``    ``for` `(i = ``0``; i < row; i++)``    ``{``        ``for` `(j = ``0``; j < col; j++)``        ``{` `            ``if` `(s[i][j] == ``'E'``)` `                ``// Since an enemy is present``                ``// Return 0 denoting No as output``                ``return` `0``;``        ``}``    ``}` `    ``// Since all enemies are killed``    ``// Return 1 denoting Yes as output``    ``return` `1``;``}` `// Driver Code``public` `static` `void` `main(String[] args)``{``    ``// Get the input matrix``    ``char` `[][]s = { ``"XXEX"``.toCharArray(),``                ``"XBXX"``.toCharArray(),``                ``"XEXX"``.toCharArray(),``                ``"XXBX"``.toCharArray() };` `    ``// Calculate Rows and columns of the String``    ``int` `row = s.length,``        ``col = s[``0``].length;` `    ``// Check if all enemies will be killed or not``    ``if` `(Kill_Enemy(s, row, col) == ``1``)``        ``System.out.print(``"Yes"``);``    ``else``        ``System.out.print(``"No"``);``}``}` `// This code is contributed by Rajput-Ji`

## Python3

 `# Python3 program to kill all enemies` `# Function to find Enemies killed or not``def` `Kill_Enemy(s, row, col):``    ``i, j, x, y ``=` `0``, ``0``, ``0``, ``0``;` `    ``# Loop to evaluate the Bomb``    ``for` `i ``in` `range``(row):``        ``for` `j ``in` `range``(col):``            ` `            ``# Check if this index is a bomb``            ``if` `(s[i][j] ``=``=` `'B'``):` `                ``# Kill all enemies``                ``# in horizontal direction``                ``for` `x ``in` `range``(row):``                    ``if` `(s[x][j] !``=` `'B'``):``                        ``s[x][j] ``=` `'X'``;` `                ``# Kill all enemies``                ``# in vertical direction``                ``for` `y ``in` `range``(col):``                    ``if` `(s[i][y] !``=` `'B'``):``                        ``s[i][y] ``=` `'X'``;` `    ``# All bombs have been found` `    ``# Check if any enemy is still present``    ``for` `i ``in` `range``(row):``        ``for` `j ``in` `range``(col):` `            ``if` `(s[i][j] ``=``=` `'E'``):` `                ``# Since an enemy is present``                ``# Return 0 denoting No as output``                ``return` `0``;` `    ``# Since all enemies are killed``    ``# Return 1 denoting Yes as output``    ``return` `1``;` `# Driver Code``if` `__name__ ``=``=` `'__main__'``:` `    ``# Get the input matrix``    ``s ``=` `[[``'X'``,``'X'``,``'E'``,``'X'``],``        ``[``'X'``,``'B'``,``'X'``,``'X'``],``        ``[``'X'``,``'E'``,``'X'``,``'X'``],``        ``[``'X'``,``'X'``,``'B'``,``'X'``]]` `    ``# Calculate Rows and columns of the String``    ``row ``=` `len``(s);``    ``col ``=` `len``(s[``0``]);` `    ``# Check if all enemies will be killed or not``    ``if` `(Kill_Enemy(s, row, col) ``=``=` `1``):``        ``print``(``"Yes"``);``    ``else``:``        ``print``(``"No"``);` `# This code is contributed by Rajput-Ji`

## C#

 `// C# program to kill all enemies``using` `System;` `class` `GFG``{` `// Function to find Enemies killed or not``static` `int` `Kill_Enemy(``char` `[,]s,``                      ``int` `row, ``int` `col)``{``    ``int` `i, j, x, y;` `    ``// Loop to evaluate the Bomb``    ``for` `(i = 0; i < row; i++)``    ``{``        ``for` `(j = 0; j < col; j++)``        ``{` `            ``// Check if this index is a bomb``            ``if` `(s[i, j] == ``'B'``)``            ``{` `                ``// Kill all enemies``                ``// in horizontal direction``                ``for` `(x = 0; x < row; x++)``                ``{``                    ``if` `(s[x, j] != ``'B'``)``                        ``s[x, j] = ``'X'``;``                ``}` `                ``// Kill all enemies``                ``// in vertical direction``                ``for` `(y = 0; y < col; y++)``                ``{``                    ``if` `(s[i, y] != ``'B'``)``                        ``s[i, y] = ``'X'``;``                ``}``            ``}``        ``}``    ``}``    ` `    ``// All bombs have been found` `    ``// Check if any enemy is still present``    ``for` `(i = 0; i < row; i++)``    ``{``        ``for` `(j = 0; j < col; j++)``        ``{` `            ``if` `(s[i, j] == ``'E'``)` `                ``// Since an enemy is present``                ``// Return 0 denoting No as output``                ``return` `0;``        ``}``    ``}` `    ``// Since all enemies are killed``    ``// Return 1 denoting Yes as output``    ``return` `1;``}` `// Driver Code``public` `static` `void` `Main(String[] args)``{``    ``// Get the input matrix``    ``char` `[,]s = {{``'X'``, ``'B'``, ``'X'``, ``'X'``},``                 ``{``'X'``, ``'E'``, ``'X'``, ``'X'``},``                 ``{``'X'``, ``'X'``, ``'B'``, ``'X'``}};``    ` `    ``// Calculate Rows and columns of the String``    ``int` `row = s.GetLength(0),``        ``col = s.GetLength(1);` `    ``// Check if all enemies will be killed or not``    ``if` `(Kill_Enemy(s, row, col) == 1)``        ``Console.Write(``"Yes"``);``    ``else``        ``Console.Write(``"No"``);``}``}` `// This code is contributed by Rajput-Ji`
Output:
`Yes`

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