char* find_lcs(const char *a, int na, const char *b, int nb) {
if (na > nb) {
const char *c; int t;
c = a, a = b, b = c;
t = na, na = nb, nb = t;
}
if (na == 0)
return alloc_str(1);
if (na == 1) {
for (int i = 0; i < nb; i++) {
if (a[0] == b[i])
return substr(a, 0, 1);
}
return alloc_str(1);
}
static int t1[MAXN];
static int t2[MAXN];
int len = lcs_len(a, na, b, nb, t1);
if (len == 0)
return alloc_str(1);
int half_len = na / 2;
char *la = substr(a, 0, half_len);
char *ra = substr(a, half_len, na - half_len);
char *tb = reverse(b, nb);
char *ta = reverse(ra, na - half_len);
lcs_len(la, half_len, b, nb, t1);
lcs_len(ta, na - half_len, tb, nb, t2);
int split = -1;
for (int i = 0; i <= nb; i++) {
if (t1[i] + t2[nb-i] == len) {
split = i;
break;
}
}
char *lb = substr(b, 0, split);
char *rb = substr(b, split, nb - split);
char *sl = find_lcs(la, half_len, lb, split);
char *sr = find_lcs(ra, na - half_len, rb, nb - split);
char *ret = cat(sl, sr);
free(la), free(ra), free(ta);
free(lb), free(rb), free(tb);
free(sl), free(sr);
return ret;
}
/*测试程序*/
int main()
{
scanf("%s%s",a,b);
printf("%d\n",lcs_len(a,b,c));
return 0;
}
int main() {
int dp[MAXN];
while (scanf("%s %s", A, B) == 2) {
int len = lcs_len(A, strlen(A), B, strlen(B), dp);
printf("%d\n", len);
}
return 0;
}
int main() {
static char A[MAXN], B[MAXN];
int dp[MAXN];
while (scanf("%s %s", A, B) == 2) {
int na = strlen(A);
int nb = strlen(B);
int len = lcs_len(A, na, B, nb, dp);
char *str = find_lcs(A, na, B, nb);
printf("%d\n", len);
printf("%s\n", str);
free(str);
}
return 0;
}
int main(int argc, char **argv)
{
if (argc != 3) {
printf("Usage: %s file1 file2\n", argv[0]);
return -1;
}
char *s = read_file(argv[1]);
char *t = read_file(argv[2]);
if (s == NULL || t == NULL) {
printf("Could not open.\n");
return -2;
}
unsigned rv = lcs_len(s, t);
printf("LCS: %d\n", rv);
free(s);
free(t);
return 0;
}
