|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 |
KMP algo solution* */ /* #include<stdio.h> #include<string.h> #include<stdlib.h> #include <iostream> using namespace std; void computeLPSArray(char *pat, int M, int *lps); bool KMPSearch(char *pat, char *txt) { int M = strlen(pat); int N = strlen(txt); // create lps[] that will hold the longest prefix suffix values for pattern int *lps = (int *)malloc(sizeof(int)*M); int j = 0; // index for pat[] // Preprocess the pattern (calculate lps[] array) computeLPSArray(pat, M, lps); int i = 0; // index for txt[] while (i < N) { if (pat[j] == txt[i]) { j++; i++; } if (j == M) { //printf("Found pattern at index %d \n", i-j); return 1; j = lps[j-1]; } // mismatch after j matches else if (i < N && pat[j] != txt[i]) { // Do not match lps[0..lps[j-1]] characters, // they will match anyway if (j != 0) j = lps[j-1]; else i = i+1; } } free(lps); // to avoid memory leak return 0; } void computeLPSArray(char *pat, int M, int *lps) { int len = 0; // lenght of the previous longest prefix suffix int i; lps[0] = 0; // lps[0] is always 0 i = 1; // the loop calculates lps[i] for i = 1 to M-1 while (i < M) { if (pat[i] == pat[len]) { len++; lps[i] = len; i++; } else // (pat[i] != pat[len]) { if (len != 0) { // This is tricky. Consider the example AAACAAAA and i = 7. len = lps[len-1]; // Also, note that we do not increment i here } else // if (len == 0) { lps[i] = 0; i++; } } } } // Driver program to test above function int main() { int t,q; char txt[1000005]; char pat[1010]; cin>>t; getchar(); while(t--) { gets(txt); cin>>q; getchar(); while(q--) { gets(pat); bool f = KMPSearch(pat, txt); if(f) cout<<"y\n"; else cout<<"n\n"; } } return 0; } |
This problem also can be solved using Suffix array but gets TLE. Code as follows:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 |
#include <iostream> #include <string> #include <cstring> #include <cstdio> #include <algorithm> using namespace std; struct suffix{ int idx; char *suffixArr; }; int arr[1000001]; int res[100005]; int qry[1005]; int cmp(suffix a,suffix b) { return (strcmp(a.suffixArr,b.suffixArr)<0?1:0); } void buildSuffixArray(char *str) { int n=strlen(str); suffix SUFX[n]; for(int i=0;i<n;i++) { SUFX[i].idx=i; SUFX[i].suffixArr=(str+i); } sort(SUFX,SUFX+n,cmp); //int *arr=new int[n]; for(int i=0;i<n;i++) { arr[i]=SUFX[i].idx; } //return arr; } bool search(char *patern,char *str,int *arr) { int len=strlen(str); int m=strlen(patern); int lo=0,hi=len-1,mid; while(lo<=hi) { mid=lo+(hi-lo)/2; //int strncmp(const char *s1, const char *s2, size_t n); int r = strncmp(patern,str+arr[mid],m); if(r==0) { return 1; } else if(r<0) { hi=mid-1; } else if(r>0) { lo=mid+1; } } return 0; } int main() { int t,q; char strres[1000000]; char strqry[10000]; cin>>t; getchar(); while(t--) { gets(strres); for(int i=0;i<strlen(strres);i++) { if(strres[i]>='A' && strres[i]<='Z') res[i]=strres[i]-'A'; else res[i]=strres[i]-'a'+26; } cin>>q; getchar(); buildSuffixArray(strres); while(q--) { gets(strqry); for(int i=0;i<strlen(strqry);i++) { if(strqry[i]>='A' && strqry[i]<='Z') qry[i]=strqry[i]-'A'; else qry[i]=strqry[i]-'a'+26; } bool f = search(strqry,strres,arr); if(f) cout<<"y\n"; else cout<<"n\n"; } } return 0; } |