字符串匹配算法-kmp

int Compare(string P, int *prefix){int m = P.length();prefix[0] = -1;int k = -1;for(int i = 1; i < m; i++){while(k >= 0 && P[k + 1] != P[i])k = prefix[k];if(P[k + 1] == P[i])k = k + 1;prefix[i] = k;}}//判读P是否是T的子串void Kmp(string T, string P){int n = T.length();int m = P.length();int prefix[m];Compare(P, prefix);int k = -1;for(int i = 0; i < n; i++){while(k >= 0 && P[k + 1] != T[i])k = prefix[k];if(P[k + 1] == T[i])k = k + 1;if(k == m - 1){cout << " I found " << i - m + 1 << endl;k = prefix[k];}}}

下面是判读T和P是否是循环数，如“strstr”和"trstrs"就是循环数。

int Compare(string P, int *prefix){int m = P.length();prefix[0] = -1;int k = -1;for(int i = 1; i < m; i++){while(k >= 0 && P[k + 1] != P[i])k = prefix[k];if(P[k + 1] == P[i])k = k + 1;prefix[i] = k;}}//判读T和P是否是循环数，如“strstr”和"trstrs"就是循环数。bool Kmp(string T, string P){int n = T.length();int m = P.length();if(n != m)return false;int prefix[m];Compare(P, prefix);int k = -1;for(int i = 0; i < 2*n - 1; i++){while(k >= 0 && P[k + 1] != T[i % n])k = prefix[k];if(P[k + 1] == T[i % n])k = k + 1;if(k == m - 1){//cout << " I found " << i - m + 1 << endl;return true;//k = prefix[k];}if(i == n -1 && -1 == k)break;}return false;}

变量和函数的名字都欠缺考虑，希望不要见怪！