POJ2945 Find the Clones trie树

建一颗$trie$树（当然你哈希也资瓷），边插边更新，看看搜到最底时有多少个字符串，然后更新。

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<cctype>
#include<cstdlib>
#include<vector>
#include<queue>
#include<map>
#include<set>
#define ll long long
#define R register int
using namespace std;
namespace Fread {
    static char B[1<<15],*S=B,*D=B;
    #define getchar() (S==D&&(D=(S=B)+fread(B,1,1<<15,stdin),S==D)?EOF:*S++)
    inline int g() {
        R ret=0,fix=1; register char ch; while(!isdigit(ch=getchar())) fix=ch==‘-‘?-1:fix;
        do ret=ret*10+(ch^48); while(isdigit(ch=getchar())); return ret*fix;
    } inline bool isempty(const char& ch) {return ch<=36||ch>=127;}
    inline void gs(char* s) {register char ch; while(isempty(ch=getchar())); do *s++=ch; while(!isempty(ch=getchar()));}
}using Fread::g; using Fread::gs;
const int N=400010;
int t[N][4],cnt[N],tot,ans[N],n,m;
inline int calc(const char& ch) {
    if(ch==‘A‘) return 0;
    else if(ch==‘C‘) return 1;
    else if(ch==‘G‘) return 2;
    return 3;
}
inline void ins(char* s) { R len=strlen(s),now=0;
    for(R i=0;i<len;++i) {
        R ch=calc(s[i]);
        if(!t[now][ch]) t[now][ch]=++tot;
        now=t[now][ch];
    } --ans[cnt[now]],++ans[++cnt[now]];
}
signed main() {
#ifdef JACK
    freopen("NOIPAK++.in","r",stdin);
#endif
    while(~scanf("%d%d",&n,&m)) {
        memset(ans,0,sizeof(ans)),memset(t,0,sizeof(t)),
        memset(cnt,0,sizeof(cnt)),tot=0;
        for(R i=1;i<=n;++i) {register char s[30]; scanf("%s",s),ins(s);}
        for(R i=1;i<=n;++i) printf("%d\n",ans[i]);
    }
}

原文地址：https://www.cnblogs.com/Jackpei/p/11013610.html