玩具取名「HAOI2008」

Posted 2022-12-07 ilverene

题意

给定一系列规则：某个长度为2的字符串可以化为某个长度为1的字符串。对于给出的字符串，求可以化为哪些长度为1的字符串。

题目所涉及字符串均由W,I,N,G组成。

---

思路

区间dp。

子状态\(dp[l][r][i]\)表示区间[l,r]是否可以化为i。

枚举断点合并即可。

代码

#include <bits/stdc++.h>

using namespace std;

namespace StandardIO 

    template<typename T>inline void read (T &x) 
        x=0;T f=1;char c=getchar();
        for (; c<'0'||c>'9'; c=getchar()) if (c=='-') f=-1;
        for (; c>='0'&&c<='9'; c=getchar()) x=x*10+c-'0';
        x*=f;
    

    template<typename T>inline void write (T x) 
        if (x<0) putchar('-'),x*=-1;
        if (x>=10) write(x/10);
        putchar(x%10+'0');
    



using namespace StandardIO;

namespace Project 
    
    const int N=202;
    
    int n;
    int o,p,q,r;
    int trn[4][4][4],dp[N][N][4];
    char s[N];
    
    inline int trans (char x) 
        if (x=='W') return 0;
        if (x=='I') return 1;
        if (x=='N') return 2;
        if (x=='G') return 3;
    

    inline void MAIN () 
        read(o),read(p),read(q),read(r);
        for (register int i=1; i<=o; ++i) 
            char a,b;scanf("%c%c",&a,&b);getchar();
            trn[trans(a)][trans(b)][0]=1;
        
        for (register int i=1; i<=p; ++i) 
            char a,b;scanf("%c%c",&a,&b);getchar();
            trn[trans(a)][trans(b)][1]=1;
        
        for (register int i=1; i<=q; ++i) 
            char a,b;scanf("%c%c",&a,&b);getchar();
            trn[trans(a)][trans(b)][2]=1;
        
        for (register int i=1; i<=r; ++i) 
            char a,b;scanf("%c%c",&a,&b);getchar();
            trn[trans(a)][trans(b)][3]=1;
        
        scanf("%s",s+1),n=strlen(s+1);
        for (register int i=1; i<=n; ++i) 
            dp[i][i][0]=(s[i]=='W');
            dp[i][i][1]=(s[i]=='I');
            dp[i][i][2]=(s[i]=='N');
            dp[i][i][3]=(s[i]=='G');
        
        for (register int len=2; len<=n; ++len) 
            for (register int l=1,r=l+len-1; r<=n; ++l,++r) 
                for (register int k=l; k<r; ++k) 
                    for (register int i=0; i<4; ++i) 
                        for (register int x=0; x<4; ++x) 
                            if (!dp[l][k][x]) continue;
                            for (register int y=0; y<4; ++y) 
                                if (!dp[k+1][r][y]) continue;
                                if (!trn[x][y][i]) continue;
                                dp[l][r][i]=1;
                            
                        
                    
                
            
        
        int flag=0;
        if (dp[1][n][0]) flag=1,printf("W");
        if (dp[1][n][1]) flag=1,printf("I");
        if (dp[1][n][2]) flag=1,printf("N");
        if (dp[1][n][3]) flag=1,printf("G");
        if (!flag) printf("The name is wrong!");
    
    


int main () 
//  freopen(".in","r",stdin);
//  freopen(".out","w",stdout);
    Project::MAIN();