C PROGRAM FOR 8 QUEENS PROBLEM USING BACKTRACKING

				//8 QUEEN PROBLEM ALGORITHM BY PRIANCEU PANDEY
				#include 
				#include 
				#define BOOL int;
				#define TRUE 1;
				#define FALSE 0;
				int check(void);
				int  queen(int i);
				int a[8][8];
				main()
				{
				int i,j,k;
				clrscr();
				for(i=0;i					{
						for(j=0;j						a[i][j]=0;
					}
				queen(0);
				
				
				for(i=0;i					{
						for(j=0;j						{
						printf("%d",a[i][j]);
						}
						printf("\n");
					}
				getche();
				return 0;
				}
				
				int check(void)
				{
				int i,j,k;
				for(i=0;i				{
					for(j=0;j					{
					if(a[i][j]==1)
					{
						for(k=0;k						{
						if((k!=i)&&(a[k][j]==1))
						return 0;
						}
						for(k=0;k						{
						if((k!=j)&&(a[i][k]==1))
						return 0;
						}
						for(k=1;((i+k)						{
						if(a[i+k][j+k]==1)
						return 0;
						}
						for(k=1;((i-k)>=0)&&((j-k)>=0);k++)
						{
						if(a[i-k][j-k]==1)
						return 0;
						}
						for(k=1;((i-k)>=0)&&((j+k)						{
						if(a[i-k][j+k]==1)
						return 0;
						}
						for(k=1;((i+k)0);k++)
						{
						if(a[i+k][j-k]==1)
						return 0;
						}
				
					}
					}
				}
				return 1;
				}
				
				int queen(int i)
				{
				int j;
				if(i>7)
					return 1;
				
				
				for(j=0;j				{
					int x=0,y=0;
					a[i][j]=1;
					x=check();
					if(x==0)
					{
					a[i][j]=0;
					continue;
					}
					else{
					y=queen(i+1);
					if (y==0)
					{
					a[i][j]=0;
					continue;
					}
					else if (y==1)
					break;
					}
				}
				if(j>=8)
					return 0;
				else
					return 1;
				}