Implementation of guessing games in C + +

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
main()
{
 int a,b;
 char c;
  srand(time(NULL));
 a=1+(rand()%1000);
 Printf ("I have a number between 1 and 1000 \ n can you guess the number I want? \ n please enter your guess. \ n");
 scanf("%d",&b);
 while(b!=-1)
 {
 if(b==a)
 {
 Printf ("correct answer \ ndo you want to play again (yes or no)?");
 scanf("%c",&c);
 scanf("%c",&c);
 switch(c){
 case 'y':
  Printf ("I have a number between 1 and 1000 \ n can you guess the number I want? \ n please enter your guess. \ n");
     scanf("%d",&b);
  break;
 case 'n':
  break;
 }
 }

 while(b<a)
 
 {
 Printf ("too little, try again \ n");
 scanf("%d",&b);
 }

 while(b>a)
 {
 Printf ("too large, try again \ n");
 scanf("%d",&b);
 }
 }
}