LeetCode 115. Distinct Subsequences
Solution1:
不会做。。
参考网址:https://www.youtube.com/watch?v=mPqqXh8XvWY
Time complexity:
Space complexity:
class Solution {
public:
int numDistinct(string s, string t) {
int ls = s.size(), lt = t.size();
vector<vector<int> > dp(lt + 1, vector<int>(ls + 1));
fill(begin(dp[0]), end(dp[0]), 1);
for (int i = 1; i <= lt; i++) {
for (int j = 1; j <= ls; j++) {
if (t[i-1] == s[j-1])
dp[i][j] = dp[i-1][j-1] + dp[i][j-1];
else
dp[i][j] = dp[i][j-1];
}
}
return dp[lt][ls];
}
};