# N-Queen problem in C.

`01 #include<stdio.h>02 #include<math.h>03 int board[30],count=0;04 void queen(int);05 int placeQueen(int);06 void printSolution(int);07 08 int main()09 {10     int i,n;11     printf("Queens Implementationn");12     printf("Enter the number of Queensn");13     scanf("%d",&n);14     queen(n);15     printf("nTotal solutions = %d",count);16     return 0;17 }18 19 int placeQueen(int pos)20 {21     int i;22     for(i=1; i<pos; i++)23     {24         if((board[i]==board[pos])||((abs(board[i]-board[pos])==abs(i-pos))))25             return 0;26     }27     return 1;28 }29 30 void printSolution(int n)31 {32     int i,j;33     count++;34     printf("nnSolution [ %d ] :n",count);35     for(i=1; i<=n; i++)36     {37         for(j=1; j<=n; j++)38         {39             if(board[i]==j)40                 printf("Qt");41             else42                 printf("*t");43         }44         printf("n");45     }46 }47 void queen(int n)48 {49     int k=1;50     board[k]=0;51     while(k!=0)52     {53         board[k]=board[k]+1;54         while((board[k]<=n)&&!placeQueen(k))55             board[k]++;56         if(board[k]<=n)57         {58             if(k==n)59                 printSolution(n);60             else61             {62                 k++;63                 board[k]=0;64             }65         }66         else67             k--;68     }69 }`
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` OUTPUT :  Queens Implementation Enter the number of Queens 4   Solution [ 1 ] : *  Q  *  * *  *  *  Q Q  *  *  * *  *  Q  *   Solution [ 2 ] : *  *  Q  * Q  *  *  * *  *  *  Q *  Q  *  *  Total solutions = 2 `