Question

Need this 8 queen code with same exact solution without goto.

Need to keep the code as similar as possible.

#include <iostream>
#include <cmath>
using namespace std;
int main(){
int q[8], c = 0, i, j,count=0;
q[0] = 0; //first queen top corner
nc: c++;
if(c == 8 ) goto print;
q[c] = -1;
nr: q[c]++;
if(q[c] == 8) goto backtrack;
for(i= 0; i < c; i++) {
if((q[i] == q[c])||(c - i == abs(q[c] - q[i]))) goto nr;
}
goto nc;
backtrack: c--;

if(c == -1) return 0;
goto nr;
print: cout << ++count <<endl;
for(i = 0; i < 8; i++){
for(j= 0; j < 8; j++){
if(q[i] == j){
cout << 1;
}
else {
cout << 0;
}
}
cout << endl;

}

goto backtrack;
}

Answer 1

#include<iostream>

#include<cmath>

using namespace std;

int q[8],c=0,i,j,count=0;

q[0]=0;

void nc()

{

c++;

}

void nr()

{

q[c]++;

}

void backtrack()

{

c--;

}

void print()

{

cout<<++count<<endl;

}

int main()

{

if(c==8) print();

q[c]=-1;

if(q[c]==8) backtrack();

for(i=0;i<c;i++)

{

if((q[i]==q[c])||(c-i==abs(q[c]-q[i])))

nr();

}

nc();

if(c==-1)

return 0;

nr();

for(i=0;i<8;i++)

{

for(j=0;j<8;j++)

{

if(q[i]==j)

{

cout<<1;

}

else

{

cout<<0;

}

}

cout<<endl;

}

backtrack();

}

Reference :

Explanation :

I have used functions to avoid goto statement. Just used function calling in the place of goto statement .

I didn't change the code , just declared the functions and variables out of the main function .