HDU 1867 A + B for you again（KMP）

题目链接：点击打开链接

思路：KMP水题。

// HDU 1876 A + B for you again 运行/限制：46ms/1000ms#include <cstdio>#include <cstring>#include <iostream>using namespace std;char s[100005], p[100005];int Next[100005];void getNext(char s[], int n) {int i, j;i = -1;j = 0;Next[0] = -1;while (j < n) {if (i == -1 || s[i] == s[j]) {i++;j++;if (s[j] == s[i]) {Next[j] = Next[i];}else {Next[j] = i;}}else {i = Next[i];}}}int kmp(char s[], char p[], int n, int m) {int i, j;i = j = 0;getNext(s, n);while (j < m) {if (i == -1 || s[i] == p[j]) {i++;j++;}else {i = Next[i];}}return i;}int main(){int n, m, x, y;while (scanf("%s%s", s, p) != EOF) {n = strlen(s);m = strlen(p);x = kmp(s, p, n, m);y = kmp(p, s, m, n);if (x > y || (x == y && strcmp(p, s) < 0)) {printf("%s%s\n", p, s + x);}else {printf("%s%s\n", s, p + y);}}    return 0;}