KMP算法模板（C++实现）

/*参考《算法导论》

My Code:*/

#include <iostream>
#include <cstdio>
#include <string>

using namespace std;

const int N = 1000;

string T, P;
int pi
;

void COMPUTER_PREFIX_FUNCTION(string P){
int m = P.length(), i, k;
for(k = pi[0] = -1, i = 1; i < m; i++){
while(k > -1 && P[k+1] != P[i])
k = pi[k];
if(P[k+1] == P[i])
k++;
pi[i] = k;
}
cout << "COMPUTER-PREFIX-FUNCTION" << endl;
for(i = 0; i < m; i++){
cout << pi[i] << " ";
}
cout << endl << endl;
}

void KMP_MATCHER(string T, string P){

int i, n, m, k;
n = T.length(); m = P.length();

for(k = -1, i = 0; i < n; i++){
while(k > -1 && P[k+1] != T[i])    k = pi[k];
if(P[k+1] == T[i])    k++;
if(k == m-1){
cout << "Pattern occurs with shift " << i - m + 2 << endl;
k = pi[k];
}
}
}

int main(){
//freopen("data.in", "r", stdin);

cin >> T >> P;
COMPUTER_PREFIX_FUNCTION(P);
KMP_MATCHER(T, P);
return 0;
}