【HDOJ】1867 A + B for you again

KMP算法的应用。

 #include <stdio.h>
 #include <string.h>

 #define MAXNUM 100005

 char src[MAXNUM], des[MAXNUM];
 char src1[MAXNUM*], des1[MAXNUM*];
 int next[MAXNUM];

 void getnext(char *p, int *next, int len) {
     int j, k;
     j = ;
     k = -;
     next[] = -;
     while (j+ < len) {
         if (k==- || p[j]==p[k]) {
             ++j;
             ++k;
             if (p[j] == p[k])
                 next[j] = next[k];
             else
                 next[j] = k;
         } else {
             k = next[k];
         }
     }
 }

 int kmp(char *src, char *des, int lens, int lend) {
     int i, j;

     i = j = ;
     memset(next, , sizeof(next));
     getnext(des, next, lend);
     while (i < lens) {
         while (src[i] != des[j]) {
             if (next[j] == -) {
                 j = ;
                 break;
             }
             j = next[j];
         }
         if (src[i] == des[j])
             ++j;
         ++i;
     }

     return j;
 }

 int main() {
     int i, j, k;
     char *p, *q;
     int lens, lend;

     while (scanf("%s %s", src, des) != EOF) {
         lens = strlen(src);
         lend = strlen(des);
         j = kmp(src, des, lens, lend);
         k = kmp(des, src, lend, lens);
         if (j == k) {
             strcpy(src1, src);
             for (i=j; i<lend; ++i)
                 src1[lens++] = des[i];
             src1[lens] = '\0';
             strcpy(des1, des);
             for (i=k; i<lens; ++i)
                 des1[lend++] = src[i];
             des1[lend] = '\0';
             if (strcmp(src1, des1) < ) {
                 printf("%s\n", src1);
             } else {
                 printf("%s\n", des1);
             }
             continue;
         } else if (j > k) {
             p = src;
             q = des;
         } else {
             p = des;
             q = src;
             j = k;
         }
         printf("%s", p);
         printf("%s\n", q+j);
     }

     return ;
 }