Ultraviolet A 11475-extend to palindrome (KMP)

Link: Ultraviolet A 11475-extend to palindrome

Given a string, the minimum number of characters to be added to the output makes the string a return string.

Solution: use string transpose as KMP, then use the original string to match, and finally the matching length is the repeated length.

#include <cstdio>#include <cstring>#include <algorithm>using namespace std;const int maxn = 1e5+5;char s[maxn], t[maxn];int n, jump[maxn];void get_jump () {    int p = 0;    for (int i = 2; i <= n; i++) {        while (p && s[p + 1] != s[i])            p = jump[p];        if (s[p + 1] == s[i])            p++;        jump[i] = p;    }}int find () {    int p = 0;    for (int i = 1; i <= n; i++) {        while (p && s[p + 1] != t[i])            p = jump[p];        if (s[p + 1] == t[i])            p++;    }    return p;}int main () {    while (scanf("%s", s + 1) == 1) {        printf("%s", s+1);        n = strlen(s + 1);        for (int i = 1; i <= n + 1; i++)            t[i] = s[i];        reverse(s + 1, s + n + 1);        get_jump();        int k = find();        for (int i = k + 1; i <= n; i++)            printf("%c", s[i]);        printf("\n");    }    return 0;}

Ultraviolet A 11475-extend to palindrome (KMP)