add: DESCRIPTIONS

cpp/2203/220305-CN.cpp

@@ -1,6 +1,14 @@
 #include <string>
 #include <iostream>
 
+/**
+ * 521. Longest Uncommon Subsequence I
+ * Given two strings a and b, return the length of the longest uncommon subsequence between a and b. If the longest uncommon subsequence does not exist, return -1.
+ * An uncommon subsequence between two strings is a string that is a subsequence of one but not the other.
+ * A subsequence of a string s is a string that can be obtained after deleting any number of characters from s.
+ * For example, "abc" is a subsequence of "aebdc" because you can delete the underlined characters in "aebdc" to get "abc". Other subsequences of "aebdc" include "aebdc", "aeb", and "" (empty string).
+ */
+
 class Solution {
 public:
 	// clang does not accept constexpr

cpp/2203/220306-CN.cpp

@@ -1,6 +1,17 @@
 #include <vector>
 #include <iostream>
 
+/**
+ * 2100. Find Good Days to Rob the Bank
+ * You and a gang of thieves are planning on robbing a bank. You are given a 0-indexed integer array security, where security[i] is the number of guards on duty on the ith day. The days are numbered starting from 0. You are also given an integer time.
+ * The ith day is a good day to rob the bank if:
+ * There are at least time days before and after the ith day,
+ * The number of guards at the bank for the time days before i are non-increasing, and
+ * The number of guards at the bank for the time days after i are non-decreasing.
+ * More formally, this means day i is a good day to rob the bank if and only if security[i - time] >= security[i - time + 1] >= ... >= security[i] <= ... <= security[i + time - 1] <= security[i + time].
+ * Return a list of all days (0-indexed) that are good days to rob the bank. The order that the days are returned in does not matter.
+ */
+
 class Solution {
 public:
 	static std::vector<int> goodDaysToRobBank(const std::vector<int>& security, int time) {

cpp/2203/220306.cpp

@@ -1,5 +1,12 @@
 #include <iostream>
 
+/**
+ * 1359. Count All Valid Pickup and Delivery Options
+ * Given n orders, each order consist in pickup and delivery services.
+ * Count all valid pickup/delivery possible sequences such that delivery(i) is always after of pickup(i).
+ * Since the answer may be too large, return it modulo 10^9 + 7.
+ */
+
 class Solution {
 private:
 	inline static const int MOD = 1000000007;