Merge pull request #1060 from julienChemillier/patch-12

Add 130 in c language

Author: Ahmad-A0

Diff for: c/130-Surrounded-Regions.c

@@ -0,0 +1,48 @@
+/*
+Given an m x n matrix board containing 'X' and 'O', capture all regions that are 4-directionally surrounded by 'X'.
+Time: O(n^2)
+Space: O(1)
+*/
+
+
+void dfsModifyBorder(char** board, int n, int m, int i, int j) {
+    if (board[i][j]=='X')
+        return;
+    board[i][j]='T';
+    if (i>0 && board[i-1][j]=='O')
+        dfsModifyBorder(board, n, m, i-1, j);
+    if (j>0 && board[i][j-1]=='O')
+        dfsModifyBorder(board, n, m, i, j-1);
+    if (i<(n-1) && board[i+1][j]=='O')
+        dfsModifyBorder(board, n, m, i+1, j);
+    if (j<(m-1) && board[i][j+1]=='O')
+        dfsModifyBorder(board, n, m, i, j+1);
+}
+
+void reModifyBorder(char** board, int n, int m) {
+    int i, j;
+    for (i=0; i<n; i++){
+        for (j=0; j<m; j++){
+            if (board[i][j]=='O')
+                board[i][j]='X';
+            else if (board[i][j]=='T')
+                board[i][j]='O';
+        }
+    }
+}
+                
+void solve(char** board, int boardSize, int* boardColSize){
+    int i, j;
+    int m = (*boardColSize);
+    int n1 = boardSize-1;
+    int m1 = m-1;
+    for (i=1; i<n1; i++) {
+        dfsModifyBorder(board, boardSize, m, i, 0);
+        dfsModifyBorder(board, boardSize, m, i, m1);
+    }
+    for (j=0; j<m; j++) {
+        dfsModifyBorder(board, boardSize, m, 0, j);
+        dfsModifyBorder(board, boardSize, m, n1, j);
+    }
+    reModifyBorder(board, boardSize, m);
+}