Create minimum_steps_to_reach_target.cpp

Author: avidLearnerInProgress

minimum_steps_to_reach_target.cpp

@@ -0,0 +1,78 @@
+// { Driver Code Starts
+#include<bits/stdc++.h>
+using namespace std;
+
+ // } Driver Code Ends
+
+class Node {
+    public: 
+    int x, y, distance;
+    Node(int x, int y, int dist) : x(x), y(y), distance(dist) {}
+};
+
+class Solution 
+{   
+    bool isInsideBoard(int x, int y, int N) {
+        return (x >= 1 and x <= N and y >= 1 and y <= N);
+    }
+    
+    public:
+    //Function to find out minimum steps Knight needs to reach target position.
+	int minStepToReachTarget(vector<int>&KnightPos,vector<int>&TargetPos,int N)
+	{
+	    // Code here
+	    
+	    queue<Node> q;
+	    
+	    // generate first 4 pairs ....
+	    // and then invert for next 4 pairs
+	    int dx[8] = {-2, -2,  2,  2,  -1,  1, -1,  1};
+	    int dy[8] = {-1,  1, -1,  1,  -2, -2,  2,  2};
+        
+        vector<vector<bool> > visited(N + 1, vector<bool>(N + 1, false));
+        
+	    q.push(Node(KnightPos[0], KnightPos[1], 0));
+	    
+	    visited[KnightPos[0]][KnightPos[1]] = true;
+	    
+	    while(!q.empty()) {
+	        
+	        // grab front and pop
+	        Node current = q.front();
+	        q.pop();
+	        
+	        // exit condition
+	        if(current.x == TargetPos[0] and current.y == TargetPos[1]) return current.distance;
+	        
+	        // push neighbors
+	        for(int i = 0; i < 8; i++) {
+	            int nx = current.x + dx[i];
+	            int ny = current.y + dy[i];
+	            
+	            if(isInsideBoard(nx, ny, N) and !visited[nx][ny]) {
+	                visited[nx][ny] = true;
+	                q.push(Node(nx, ny, current.distance + 1));
+	            }
+	        }
+	    }
+	    return -1; // knight unreachable to its target
+	}
+};
+
+// { Driver Code Starts.
+int main(){
+	int tc;
+	cin >> tc;
+	while(tc--){
+		vector<int>KnightPos(2);
+		vector<int>TargetPos(2);
+		int N;
+		cin >> N;
+		cin >> KnightPos[0] >> KnightPos[1];
+		cin >> TargetPos[0] >> TargetPos[1];
+		Solution obj;
+		int ans = obj.minStepToReachTarget(KnightPos, TargetPos, N);
+		cout << ans <<"\n";
+	}
+	return 0;
+}  // } Driver Code Ends