uva 10029

#include <stdio.h>#include <string.h>#define max(a, b) (a) > (b) ? (a) :(b)const int N = 25005;const int M = 20;int n = 0, dp[N], ans = 1;char word[N][M];void add(char *a, char *s, char ch, int in) {int i;for (i = 0; i < in; i++)s[i] = a[i];s[in] = ch;for ( ; a[i]; i++)s[i + 1] = a[i];s[i + 1] = '\0';}void del (char *a, char *s, int in) {int i;for (i = 0; i < in; i++)s[i] = a[i];for (i++; a[i]; i++)s[i - 1] = a[i];s[i - 1] = '\0';}void change(char *a, char *s, char ch, int in) {int i;for (i = 0; a[i]; i++)s[i] = a[i];    s[in] = ch;s[i] = '\0';}void handle(char *now, char *s, char ch, int t, int flag) {if (flag == 0) change(now, s, ch, t);else if (flag == 1) del(now, s, t);else add(now, s, ch, t);}int search(char *s, int r) {r--;int l = 0, mid;while (l <= r) {mid = (l + r) / 2;int flag = strcmp(word[mid], s);if (flag == 0) return mid;else if (flag < 0) l = mid + 1;else r = mid - 1;}return -1;}int main() {char str[M];while (scanf("%s", word[n]) == 1) n++;for (int i = 0; i < n; i++) {dp[i] = 1;for (int k = 0; k < 3; k++) {for (int j = 0; word[i][j]; j++) {for (int t = 0; t < 26; t++) {handle(word[i], str, 'a' + t, j, k);if (strcmp(word[i], str) < 0) break;int f = search(str, i);if (f >= 0)dp[i] = max(dp[i], dp[f] + 1);}}}ans = max(ans, dp[i]);}printf("%d\n", ans);return 0;}