n-queen.rar_queen

#include<iostream.h> #include<stdlib.h> int **a; int *h; bool put(int i,int j,int n) { int r,s; for(r=0;r<n;r++) { for(s=0;s<n;s++) { if(a[i][r]==1||a[s][j]==1){break;} if( (((r+s)==(i+j)) || ((r-s)==(i-j)) )&&(a[r][s]==1)){break;} } if(s!=n)break;//充分说明了在循环体里定义的变量出了循环体就不能用。 } if(r!=n||s!=n)return false; else return true; } void trial(int i,int n) { int j; if(i>n-1) { cout<<"the site of the queen is"<<endl; for(int p=0;p<n;p++) { for(int q=0;q<n;q++) { if(a[p][q]==1)cout<<p<<q; } cout<<endl; } char v; cout<<"if you want to continue,please put in Y/y"<<endl; cin>>v; if(v=='y'||v=='Y') { i=i-1;int z=h[i]; a[i][z]=0; } else exit(2); } else { for(j=0;j<n;j++) { if(put(i,j,n)) { a[i][j]=1;h[i]=j; trial(i+1,n); } } if(j==n) { if(i>0) { i=i-1;int z=h[i]; a[i][z]=0; } else cout<<"search has been finished!"<<endl; }//递归也要返回到原状态。。很郁闷，是程序设计的问题？？ } } void main() { int n; cout<<"please put in the number of the queen"<<endl; cin>>n; a=new int*[n]; h=new int[n]; int i=0; for(int p=0;p<n;p++) { a[p]=new int[n]; for(int q=0;q<n;q++) {a[p][q]=0;} } trial(i,n); }