The 2016 ACM-ICPC Asia Beijing Regional Contest E - What a Ridiculous Election

https://vjudge.net/contest/259447#problem/E

bfs，k个限制条件以数组的额外k维呈现。

 #include <bits/stdc++.h>
 using namespace std;
 #define ll long long
 #define minv 1e-6
 #define inf 1e9
 #define pi 3.1415926536
 #define nl 2.7182818284
 const ll mod=1e9+;//
 const int maxn=1e5+;

 int qx[maxn*],qy[maxn*],num[maxn*],step[maxn*],ci[maxn],c[]={,,,,},d[];
 bool vis[maxn][][];

 int main()
 {
     int head,tail,i,j,s,x,y,ss,bu;
     head=,tail=;
     for (i=;i<1e5;i++)
         ci[i]=inf;
     qx[]=,qy[]=,num[]=,step[]=,ci[]=,vis[][][]=;
     while (head<tail)
     {
         head++;
         s=num[head];
         x=qx[head];
         y=qy[head];
         bu=step[head]+;
         ss=s;
         for (i=;i<;i++)
             d[i]=ss%,ss/=;
         for (i=;i<;i++)
         {
             j=i+;
             ss=s+(c[i]-c[j])*(d[j]-d[i]);
             if (!vis[ss][x][y])
             {
                 tail++;
                 qx[tail]=x;
                 qy[tail]=y;
                 num[tail]=ss;
                 step[tail]=bu;
                 ci[ss]=min(ci[ss],bu);
                 vis[ss][x][y]=;
             }
         }
         if (x!=)
             for (i=;i<;i++)
             {
                 ss=s+c[i]*(d[i]==?-:);
                 if (!vis[ss][x-][y])
                 {
                     tail++;
                     qx[tail]=x-;
                     qy[tail]=y;
                     num[tail]=ss;
                     step[tail]=bu;
                     ci[ss]=min(ci[ss],bu);
                     vis[ss][x-][y]=;
                 }
             }
         if (y!=)
             for (i=;i<;i++)
             {
                 ss=s+c[i]*(d[i]*%-d[i]);
                 if (!vis[ss][x][y-])
                 {
                     tail++;
                     qx[tail]=x;
                     qy[tail]=y-;
                     num[tail]=ss;
                     step[tail]=bu;
                     ci[ss]=min(ci[ss],bu);
                     vis[ss][x][y-]=;
                 }
             }
     }
     while (~scanf("%d",&s))
         printf("%d\n",ci[s]==inf?-:ci[s]);
     return ;
 }