added N-queens in C

C/N_Queens.c

@@ -0,0 +1,50 @@
+//N queens
+
+#include<stdio.h>
+#include<math.h>
+
+#define MAX 100
+
+int place(int x[MAX], int r, int c)
+{
+    int i;
+    for(i=1;i<r;i++)
+        if(x[i]==c || (abs(x[i]-c)==abs(i-r)))
+            return 0;
+
+    return 1;
+}
+
+void nqueens( int x[MAX],int r, int n)
+{
+    int i,c;
+
+    for(c=1;c<=n;c++)
+    {
+        if(place(x,r,c))
+        {
+            x[r]=c;
+            if(r==n)
+            {
+                printf("{ ");
+                for(i=1;i<=n;i++)
+                    printf(" %d ",x[i]);
+                printf(" }\n");
+            }
+            else
+                nqueens(x,r+1,n);
+        }
+    }
+}
+
+int main()
+{
+    int n,i,j;
+    int x[MAX];
+
+    printf("Enter the no. of QUEENS : ");
+    scanf("%d",&n);
+
+    printf("\nThe solutions are : \n");
+    nqueens(x,1,n);
+}