C语言 | Leetcode C语言题解之第392题判断子序列
题目：
题解：
bool isSubsequence(char* s, char* t) {
int n = strlen(s), m = strlen(t);
int f[m + 1][26];
memset(f, 0, sizeof(f));
for (int i = 0; i < 26; i++) {
f[m][i] = m;
}
for (int i = m - 1; i >= 0; i--) {
for (int j = 0; j < 26; j++) {
if (t[i] == j + 'a')
f[i][j] = i;
else
f[i][j] = f[i + 1][j];
}
}
int add = 0;
for (int i = 0; i < n; i++) {
if (f[add][s[i] - 'a'] == m) {
return false;
}
add = f[add][s[i] - 'a'] + 1;
}
return true;
}