目錄

題目

解法一：動態規劃

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題目

解法一：動態規劃

int distinctSubseqII(char* s) {const int mod = 1000000007;int dp[26] = {0};int cnt = 1;int len = strlen(s);for (int i = 0; i < len; i++) {int new = (cnt - dp[s[i] - 'a'] + mod) % mod;cnt = (cnt + new) % mod;dp[s[i] - 'a'] = (dp[s[i] - 'a'] + new) % mod;}return (cnt - 1 + mod) % mod;
}