摘要： #include<stdio.h>int ans,a[22],f,step;int judge(){ int i; for(i=1;i<=20;i++) if(a[i]==1)return 0; return 1;}void change(int x){ a[x]=!a[x]; if(x-1>=1)a[x-1]=!a[x-1]; if(x+1<=20)a[x+1]=!a[x+1];}void dfs(int x,int num){ if(step==num) { if(judge()) { ... 阅读全文