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Copy pathN_queens.cpp
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N_queens.cpp
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void print_array(int* arr,int n)
{
int j=0;
while(j<n)
{
printf("%d ",arr[j]+1);
j++;
}
}
void initialize_array(int* arr,int n,int k)
{
int j=0;
while(j<n)
{
arr[j]=k;
j++;
}
}
void diagonal_of_xy_in_row_p(int x,int y,int r,int* ans1,int* ans2)
{
int diff=r-x;
*ans1=y+diff;
*ans2=y-diff;
}
void copy_arr(int* a,int* b,int n)
{
int j=0;
while(j<n)
{
a[j]=b[j];
j++;
}
}
void func(int* arr,int p,int n)
{
if(p==n)
{
print_array(arr,n);
printf("\n");
}
else
{
int place[n];
initialize_array(place,n,1);
int j=0;
while(j<p)
{
place[arr[j]]=0;
int x1,x2;
diagonal_of_xy_in_row_p(j,arr[j],p,&x1,&x2);
if(x1>=0 && x1<n)
place[x1]=0;
if(x2>=0 && x2<n)
place[x2]=0;
j++;
}
j=0;
while(j<n)
{
if(place[j]==1)
{
int* newarr=(int*)malloc(sizeof(int)*(p+1));
copy_arr(newarr,arr,p);
newarr[p]=j;
func(newarr,p+1,n);
}
j++;
}
}
}