Added N-Queens Algo

Backtracking/Queens.c

@@ -0,0 +1,54 @@
+#include<stdio.h>
+#include<math.h>
+int board[100];
+int count;
+
+void print_B(int n){
+    int i,j;
+    printf("Solution %d:\n",++count);
+    for(i=1;i<=n;i++){
+        for(j=1;j<=n;j++){
+            if(board[i]==j){
+                printf("Q\t");
+            }
+            else{
+                printf("-\t");
+            }
+        }printf("\n");
+    }
+}
+
+int place(int row, int column){
+    int i;
+    for(i=1;i<=row-1;i++){
+        if(board[i]==column){
+            return 0;
+        }
+        else if(abs(board[i]-column)==abs(i-row)){
+            return 0;
+        }
+    }
+    return 1;
+}
+
+void Queen(int row,int n){
+    int column;
+    for(column=1;column<=n;column++){
+        if(place(row,column)){
+            board[row]=column;
+            if(row==n){
+                print_B(n);
+            }
+            else{
+                Queen(row+1,n);
+            }
+        }
+    }
+}
+
+void main(){
+    int n;
+    printf("Enter No of Queens: ");
+    scanf("%d",&n);
+    Queen(1,n);
+}