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LightOJ 题目1427 - Substring Frequency (II)(AC自己主动机)
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Time Limit: 5 second(s) | Memory Limit: 128 MB |
A string is a finite sequence of symbols that are chosen from an alphabet. In this problem you are given a string T and n queries each with a string Pi, where the strings contain lower case English alphabets only. You have to find the number of times Pi occurs as a substring of T.
Input
Input starts with an integer T (≤ 10), denoting the number of test cases.
Each case starts with a line containing an integer n (1 ≤ n ≤ 500). The next line contains the string T (1 ≤ |T| ≤ 106). Each of the next n lines contains a string Pi (1 ≤ |Pi| ≤ 500).
Output
For each case, print the case number in a single line first. Then for each string Pi, report the number of times it occurs as a substring of T in a single line.
Sample Input |
Output for Sample Input |
2 5 ababacbabc aba ba ac a abc 3 lightoj oj light lit |
Case 1: 2 3 1 4 1 Case 2: 1 1 0 |
Notes
1. Dataset is huge, use faster I/O methods.
2. If S is a string then |S| denotes the length of S.
就是问子串在母串中的出现的次数(可重叠)
ac代码
#include<stdio.h> #include<string.h> #include<queue> #include<iostream> using namespace std; const int maxnode=250*1000+10000; const int sg_size=26; char str[1000100],key[550]; int pos[550]; struct Trie { int ch[maxnode][sg_size]; int val[maxnode]; int f[maxnode]; int num[maxnode]; int sz; void init() { sz=1; memset(ch,0,sizeof(ch)); memset(val,0,sizeof(val)); memset(f,0,sizeof(f)); memset(num,0,sizeof(num)); } int idx(char c) { return c-‘a‘; } int insert(char *s) { int u=0,i; for(i=0;s[i];i++) { int c=idx(s[i]); if(!ch[u][c]) ch[u][c]=sz++;; u=ch[u][c]; } val[u]++; num[u]=0; return u; } void build_ac() { queue<int>q; int i; for(i=0;i<sg_size;i++) { if(ch[0][i]) q.push(ch[0][i]); } int r,c,u,v; while(!q.empty()) { r=q.front(); q.pop(); for(c=0;c<sg_size;c++) { u=ch[r][c]; if(!u) continue; q.push(u); v=f[r]; while(v&&ch[v][c]==0) v=f[v]; f[u]=ch[v][c]; } } } void find(char *s) { int j=0; for(int i=0;s[i];i++) { int c=idx(s[i]); while(j&&ch[j][c]==0) j=f[j]; j=ch[j][c]; int temp=j; while(temp) { num[temp]++; temp=f[temp]; } } } }ac; int main() { int t,c=0; scanf("%d",&t); while(t--) { int n; scanf("%d",&n); scanf("%s",str); int i; ac.init(); for(i=1;i<=n;i++) { scanf("%s",key); pos[i]=ac.insert(key); } ac.build_ac(); ac.find(str); printf("Case %d:\n",++c); for(i=1;i<=n;i++) { printf("%d\n",ac.num[pos[i]]); } } }
LightOJ 题目1427 - Substring Frequency (II)(AC自己主动机)