2544-2547 solved.

liuyubobobo · liuyubobobo · commit e7a7615d6ee9 · 2023-01-22T01:04:04.000-08:00
diff --git a/2501-3000/2544-Alternating-Digit-Sum/cpp-2544/CMakeLists.txt b/2501-3000/2544-Alternating-Digit-Sum/cpp-2544/CMakeLists.txt
@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.24)
+project(cpp_2544)
+
+set(CMAKE_CXX_STANDARD 17)
+
+add_executable(cpp_2544 main.cpp)
diff --git a/2501-3000/2544-Alternating-Digit-Sum/cpp-2544/main.cpp b/2501-3000/2544-Alternating-Digit-Sum/cpp-2544/main.cpp
@@ -0,0 +1,29 @@
+/// Source : https://leetcode.com/problems/alternating-digit-sum/description/
+/// Author : liuyubobobo
+/// Time   : 2023-01-21
+
+#include <iostream>
+
+using namespace std;
+
+
+/// Simulation
+/// Time Complexity: O(logn)
+/// Space Complexity: O(logn)
+class Solution {
+public:
+    int alternateDigitSum(int n) {
+
+        string s = to_string(n);
+        int res = 0;
+        for(int i = 0; i < s.size(); i ++)
+            res += (i % 2 ? -1 : 1) * (s[i] - '0');
+        return res;
+    }
+};
+
+
+int main() {
+
+    return 0;
+}
diff --git a/2501-3000/2545-Sort-the-Students-by-Their-Kth-Score/cpp-2545/CMakeLists.txt b/2501-3000/2545-Sort-the-Students-by-Their-Kth-Score/cpp-2545/CMakeLists.txt
@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.24)
+project(cpp_2545)
+
+set(CMAKE_CXX_STANDARD 17)
+
+add_executable(cpp_2545 main.cpp)
diff --git a/2501-3000/2545-Sort-the-Students-by-Their-Kth-Score/cpp-2545/main.cpp b/2501-3000/2545-Sort-the-Students-by-Their-Kth-Score/cpp-2545/main.cpp
@@ -0,0 +1,31 @@
+/// Source : https://leetcode.com/problems/sort-the-students-by-their-kth-score/description/
+/// Author : liuyubobobo
+/// Time   : 2023-01-21
+
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+
+/// Sorting
+/// Time Complexity: O(mlogm * n)
+/// Space Cpomplexity: O(n)
+class Solution {
+public:
+    vector<vector<int>> sortTheStudents(vector<vector<int>>& score, int k) {
+
+        sort(score.begin(), score.end(),
+             [k](const vector<int>& s1, const vector<int>& s2){
+            return s1[k] > s2[k];
+        });
+        return score;
+    }
+};
+
+
+int main() {
+
+    return 0;
+}
diff --git a/2501-3000/2546-Apply-Bitwise-Operations-to-Make-Strings-Equal/cpp-2546/CMakeLists.txt b/2501-3000/2546-Apply-Bitwise-Operations-to-Make-Strings-Equal/cpp-2546/CMakeLists.txt
@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.24)
+project(cpp_2546)
+
+set(CMAKE_CXX_STANDARD 17)
+
+add_executable(cpp_2546 main.cpp)
diff --git a/2501-3000/2546-Apply-Bitwise-Operations-to-Make-Strings-Equal/cpp-2546/main.cpp b/2501-3000/2546-Apply-Bitwise-Operations-to-Make-Strings-Equal/cpp-2546/main.cpp
@@ -0,0 +1,38 @@
+/// Source : https://leetcode.com/problems/apply-bitwise-operations-to-make-strings-equal/description/
+/// Author : liuyubobobo
+/// Time   : 2023-01-22
+
+#include <iostream>
+
+using namespace std;
+
+
+/// Ad-Hoc
+/// Time Complexity: O(n)
+/// Space Complexity: O(1)
+class Solution {
+public:
+    bool makeStringsEqual(string s, string target) {
+
+        int n = s.size() - 1;
+        if(s == target) return true;
+
+        bool s_has1 = false, s_all0 = true;
+        for(char c: s) if(c == '1') s_has1 = true;
+        for(char c: s) if(c == '1') s_all0 = false;
+
+        bool t_has1 = false, t_all0 = true;
+        for(char c: target) if(c == '1') t_has1 = true;
+        for(char c: target) if(c == '1') t_all0 = false;
+
+        if(s_has1 && t_all0) return false;
+        if(t_has1 && s_all0) return false;
+        return true;
+    }
+};
+
+
+int main() {
+
+    return 0;
+}
diff --git a/2501-3000/2547-Minimum-Cost-to-Split-an-Array/cpp-2547/CMakeLists.txt b/2501-3000/2547-Minimum-Cost-to-Split-an-Array/cpp-2547/CMakeLists.txt
@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.24)
+project(cpp_2547)
+
+set(CMAKE_CXX_STANDARD 17)
+
+add_executable(cpp_2547 main.cpp)
diff --git a/2501-3000/2547-Minimum-Cost-to-Split-an-Array/cpp-2547/main.cpp b/2501-3000/2547-Minimum-Cost-to-Split-an-Array/cpp-2547/main.cpp
@@ -0,0 +1,43 @@
+/// Source : https://leetcode.com/problems/minimum-cost-to-split-an-array/description/
+/// Author : liuyubobobo
+/// Time   : 2023-01-22
+
+#include <iostream>
+#include <vector>
+#include <climits>
+#include <map>
+
+using namespace std;
+
+
+/// DP
+/// Time Complexity: O(n^2)
+/// Space Complexity: O(n)
+class Solution {
+public:
+    int minCost(vector<int>& nums, int k) {
+
+        int n = nums.size();
+
+        vector<int> dp(n + 1, INT_MAX / 2);
+        dp[n] = 0;
+        for(int i = n - 1; i >= 0; i --){
+            map<int, int> f;
+            int trim_value = 0;
+            for(int j = i; j >= 0; j --){
+                f[nums[j]] ++;
+                int len = f[nums[j]];
+                if(len == 2) trim_value += 2;
+                else if(len > 2) trim_value ++;
+                dp[j] = min(dp[j], trim_value + k + dp[i + 1]);
+            }
+        }
+        return dp[0];
+    }
+};
+
+
+int main() {
+
+    return 0;
+}
diff --git a/readme.md b/readme.md
@@ -2425,6 +2425,11 @@ email: [liuyubobobo@gmail.com](mailto:liuyubobobo@gmail.com)
 | 2541 | [Minimum Operations to Make Array Equal II](https://leetcode.com/problems/minimum-operations-to-make-array-equal-ii/) | [无] | [C++](2001-2500/2541-Minimum-Operations-to-Make-Array-Equal-II/cpp-2541/) | | |
 | 2542 | [Maximum Subsequence Score](https://leetcode.com/problems/maximum-subsequence-score/) | [无] | [C++](2001-2500/2542-Maximum-Subsequence-Score/cpp-2542/) | | |
 | | | | | | |
+| 2544 | [Alternating Digit Sum](https://leetcode.com/problems/alternating-digit-sum/) | [无] | [C++](2001-2500/2544-Alternating-Digit-Sum/cpp-2544/) | | |
+| 2545 | [Sort the Students by Their Kth Score](https://leetcode.com/problems/sort-the-students-by-their-kth-score/) | [无] | [C++](2001-2500/2545-Sort-the-Students-by-Their-Kth-Score/cpp-2545/) | | |
+| 2546 | [Apply Bitwise Operations to Make Strings Equal](https://leetcode.com/problems/apply-bitwise-operations-to-make-strings-equal/) | [无] | [C++](2001-2500/2546-Apply-Bitwise-Operations-to-Make-Strings-Equal/cpp-2546/) | | |
+| 2547 | [Minimum Cost to Split an Array](https://leetcode.com/problems/minimum-cost-to-split-an-array/) | [无] | [C++](2001-2500/2547-Minimum-Cost-to-Split-an-Array/cpp-2547/) | | |
+| | | | | | |
 
 ### 力扣中文站比赛 [传送门](LC/)
 
