Created
March 12, 2018 05:52
-
-
Save HYChou0515/a24fb450e14b7c387cdc52bd28bcccfd to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#include<stdio.h> | |
#include<string.h> | |
int* longestPrefixSufix(char* s); | |
int main(void) { | |
int N; | |
scanf("%d", &N); | |
for(int n = 0; n < N; n++){ | |
char s[100000]; | |
char p[100000]; | |
scanf("%s", s); | |
scanf("%s", p); | |
printf("%d\n",kmp(s,p)); | |
} | |
return 0; | |
} | |
int kmp(char* s, char* p){ | |
int* t = longestPrefixSufix(s); | |
int i=0; | |
int j=0; | |
int ls=strlen(s); | |
int lp=strlen(p); | |
while(i<ls){ | |
if(s[i]==p[j]){ | |
if(j==lp-1){ | |
return i-j; | |
}else{ | |
i++; | |
j++; | |
} | |
}else{ | |
if(j>0){ | |
j=t[j-1]; | |
}else{ | |
i++; | |
} | |
} | |
} | |
return -1; | |
} | |
int* longestPrefixSufix(char* s){ | |
int *t; | |
t = malloc(sizeof(int)*strlen(s)); | |
int i=1; | |
int j=0; | |
t[0]=0; | |
while(i<strlen(s)){ | |
if(s[i]==s[j]){ | |
t[i]=j+1; | |
i++; | |
j++; | |
}else if(j>0){ | |
j=t[j-1]; | |
}else{ | |
t[i]=0; | |
i++; | |
} | |
} | |
return t; | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment