Codeforces Round #201 (Div. 2) D. Lucky Common Subsequence

求出最長子序列，且不包含一個子字串

DP難題，要在LCS上面多開一維的空間

用來記錄病毒字串的生長，所以需要用KMP

首次深入學習了

//
//        GGGGGGGGGGGGG        CCCCCCCCCCCCC               AAA
//     GGG::::::::::::G     CCC::::::::::::C              A:::A
//   GG:::::::::::::::G   CC:::::::::::::::C             A:::::A
//  G:::::GGGGGGGG::::G  C:::::CCCCCCCC::::C            A:::::::A
// G:::::G       GGGGGG C:::::C       CCCCCC           A:::::::::A
//G:::::G              C:::::C                        A:::::A:::::A
//G:::::G              C:::::C                       A:::::A A:::::A
//G:::::G    GGGGGGGGGGC:::::C                      A:::::A   A:::::A
//G:::::G    G::::::::GC:::::C                     A:::::A     A:::::A
//G:::::G    GGGGG::::GC:::::C                    A:::::AAAAAAAAA:::::A
//G:::::G        G::::GC:::::C                   A:::::::::::::::::::::A
// G:::::G       G::::G C:::::C       CCCCCC    A:::::AAAAAAAAAAAAA:::::A
//  G:::::GGGGGGGG::::G  C:::::CCCCCCCC::::C   A:::::A             A:::::A
//   GG:::::::::::::::G   CC:::::::::::::::C  A:::::A               A:::::A
//     GGG::::::GGG:::G     CCC::::::::::::C A:::::A                 A:::::A
//        GGGGGG   GGGG        CCCCCCCCCCCCCAAAAAAA                   AAAAAAA
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <climits>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cctype>
#include <utility>
#include <ctime>
using namespace std;
#ifdef DEBUG
#define VAR(a,b) decltype(b) a=(b)
#define debug(...) printf("DEBUG: "),printf(__VA_ARGS__)
#define gettime() end_time=clock();printf("now running time is %.7f\n",(float)(end_time - start_time)/CLOCKS_PER_SEC);
#else
#define VAR(a,b) __typeof(b) a=(b)
#define debug(...)
#define gettime()
#endif
typedef unsigned int uint;
typedef long long int Int;
typedef unsigned long long int UInt;
#define Set(a,s) memset(a,s,sizeof(a))
#define Write(w) freopen(w,"w",stdout)
#define Read(r) freopen(r,"r",stdin)
#define Pln() printf("\n")
#define I_de(x,n)for(int i=0;i<n;i++)printf("%d ",x[i]);Pln()
#define De(x)printf(#x"%d\n",x)
#define For(i,x)for(int i=0;i<x;i++)
#define CON(x,y) x##y
#define Pmz(dp,nx,ny)for(int hty=0;hty<ny;hty++){for(int htx=0;htx<nx;htx++){\
    printf("%d ",dp[htx][hty]);}Pln();}
#define M 30005
#define PII pair<int,int>
#define PB push_back
#define oo INT_MAX
#define Set_oo 0x3f
#define FOR(a,b) for(VAR(a,(b).begin());a!=(b).end();++a)
#define eps 1e-6
#define X first
#define Y second
clock_t start_time=clock(), end_time;
bool xdy(double x,double y){return x>y+eps;}
bool xddy(double x,double y){return x>y-eps;}
bool xcy(double x,double y){return x<y-eps;}
bool xcdy(double x,double y){return x<y+eps;}
int min3(int x,int y,int z){
    int tmp=min(x,y);
    return min(tmp,z);
}
int max3(int x,int y,int z){
    int tmp=max(x,y);
    return max(tmp,z);
}

char virus[105],s1[105],s2[105];
int dp[128][128][128];
bool vis[128][128][128];
int acpos[105][128];
bool checkac(int pos,int i,char x){
    if(virus[pos]!=x){
        return false;
    }
    for(int j=pos-1;j>=0;j--){
        i--;
        if(virus[j]!=virus[i])return false;
    }
    return true;
}
void initac(){
    for(int i=0;virus[i];i++){
        for(int j='A';j<='Z';j++){
            for(int k=i;k>=0;k--){
                if(checkac(k,i,j)){
                    acpos[i][j]=k+1;
                    break;
                }
            }
        }
    }

}
int dfs(int pos1,int pos2,int pos3){

    if(!virus[pos3])return -oo;
    if(vis[pos1][pos2][pos3])return dp[pos1][pos2][pos3];
    vis[pos1][pos2][pos3]=1;
    if(s1[pos1]==0||s2[pos2]==0){
        return 0;
    }
    if(s1[pos1]==s2[pos2]){
        dp[pos1][pos2][pos3]=dfs(pos1+1,pos2+1,acpos[pos3][s1[pos1]])+1;
    }
    dp[pos1][pos2][pos3]=max3(dp[pos1][pos2][pos3],dfs(pos1+1,pos2,pos3),dfs(pos1,pos2+1,pos3));
    return dp[pos1][pos2][pos3];
}
void recon(int pos1,int pos2,int pos3){
    if(!virus[pos3])return;
    if(s1[pos1]==0||s2[pos2]==0)return ;
//    debug("%d %d %d\n",pos1,pos2,pos3);
    if(dp[pos1][pos2][pos3]==dp[pos1+1][pos2][pos3]){
        recon(pos1+1,pos2,pos3);
    }else if(dp[pos1][pos2][pos3]==dp[pos1][pos2+1][pos3]){
        recon(pos1,pos2+1,pos3);
    }else{
        printf("%c",s1[pos1]);
        recon(pos1+1,pos2+1,acpos[pos3][s1[pos1]]);
    }
}
int main() {
    ios_base::sync_with_stdio(0);
    while(~scanf("%s %s %s",s1,s2,virus)){
        initac();
        Set(vis,0);
        if(dfs(0,0,0)==0){
            puts("0");
        }else{
//            printf("%d\n",dfs(0,0,0));
            recon(0,0,0);
            puts("");
        }
    }
















}