CCF-CSP201803-4-棋局评估

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 #define pii pair<int,int>
 4 map<string,int>f;
 5 int blank(string str){ int res=0; for(char c:str)res+=(c==‘0‘);return res; }
 6 int check(string str){
 7     for(int i=0;i<3;++i){
 8         if(str[i*3]==‘1‘&&str[i*3+1]==‘1‘&&str[i*3+2]==‘1‘) return 1;
 9         if(str[i*3]==‘2‘&&str[i*3+1]==‘2‘&&str[i*3+2]==‘2‘) return 2;
10         if(str[i]==‘1‘&&str[i+3]==‘1‘&&str[i+6]==‘1‘) return 1;
11         if(str[i]==‘2‘&&str[i+3]==‘2‘&&str[i+6]==‘2‘) return 2;
12     }
13     if(str[0]==‘1‘&&str[4]==‘1‘&&str[8]==‘1‘||
14        str[2]==‘1‘&&str[4]==‘1‘&&str[6]==‘1‘)return 1;
15     if(str[0]==‘2‘&&str[4]==‘2‘&&str[8]==‘2‘||
16        str[2]==‘2‘&&str[4]==‘2‘&&str[6]==‘2‘)return 2;
17     return 0;
18 }
19 void dfs(string state,int cur){
20     if(f.count(state))return;
21     //cout<<state<<endl;
22     int r=check(state);
23     int b=blank(state);
24     if(r==1){
25         f[state]=-b-1;
26     }else if(r==2){
27         f[state]=-b-1;
28     }else if(b==0){
29         f[state]=0;
30     }
31     else{
32       int win=-999,lose=-999,ping=-999;
33       for(int i=0;i<=8;++i){
34         if(state[i]==‘0‘){
35             if(cur==1){
36                 state[i]=‘1‘;
37                 dfs(state,2);
38             }else if(cur==2){
39                 state[i]=‘2‘;
40                 dfs(state,1);
41             }
42              if(f[state]<0){
43                     win=max(win,-f[state]);
44                 }else if(f[state]>0){
45                     lose=max(lose,-f[state]);
46                 }else ping=1;
47             state[i]=‘0‘;
48         }
49       }
50       if(win!=-999){
51         f[state]=win;
52       }else if(ping!=-999)f[state]=0;
53       else f[state]=lose;
54     }
55 }
56 int main(){
57     int T;
58     char ch;
59     string str;
60     cin>>T;
61     while(T--){
62         str="";
63         for(int i=1;i<=9;++i){
64             cin>>ch;
65             str+=ch;
66         }
67         if(!f.count(str)){
68             dfs(str,1);
69         }cout<<f[str]<<endl;
70     }
71     return 0;
72 }