Merge pull request royalpranjal#21 from me-ydv-5/patch-1

Epic Systems, Amazon

Author: Pranjal

Graphs/WordSearchBoard.cpp

@@ -0,0 +1,49 @@
+vector<int> x({0, 1, -1, 0});
+vector<int> y({1, 0, 0, -1});
+ 
+// Check if the coordinates are safe to visit
+bool isSafe(int a, int b, int c, int d){
+    if(a >= 0 && a < c && b >= 0 && b < d)return true;
+    return false;
+}
+
+
+void explore(bool& pivot, int val, int a, int b, vector<string>& A, string B){
+    // If reached on the last index of the string,
+    // it means we have found the reqd. string and 
+    // so we return
+    if(val == B.size()-1){
+        pivot = true;
+        return;
+    }
+
+    for(int i = 0; i < x.size(); i++){
+        int first = a + x[i];
+        int second = b + y[i];
+        
+        // Explore the adjacent node only if its value is the next index in the
+        // given string
+        if(isSafe(first, second, A.size(), A[0].size()) && A[first][second] == B[val+1]){
+            explore(pivot, val+1, first, second, A, B);
+            // To reduce time limit.
+            if(pivot == true)return;
+        }
+    }
+
+}
+
+int Solution::exist(vector<string> &A, string B) {
+    int l = A.size(), m = A[0].size();
+    if(l == 0)return 0;
+
+    bool pivot = false;
+    for(int i = 0; i < l; i++){
+        for(int k = 0; k < m; k++){
+            if(A[i][k] == B[0]){
+                explore(pivot, 0, i, k, A, B);
+            }
+            if(pivot)return pivot;
+        }
+    }
+    return pivot;
+}