day 24

Author: sachuverma

Diff for: Leetcode Daily Challenge/August-2021/24. Complex Number Multiplication.cpp

@@ -0,0 +1,37 @@
+/*
+Complex Number Multiplication
+=============================
+
+A complex number can be represented as a string on the form "real+imaginaryi" where:
+
+real is the real part and is an integer in the range [-100, 100].
+imaginary is the imaginary part and is an integer in the range [-100, 100].
+i2 == -1.
+Given two complex numbers num1 and num2 as strings, return a string of the complex number that represents their multiplications.
+
+Example 1:
+Input: num1 = "1+1i", num2 = "1+1i"
+Output: "0+2i"
+Explanation: (1 + i) * (1 + i) = 1 + i2 + 2 * i = 2i, and you need convert it to the form of 0+2i.
+
+Example 2:
+Input: num1 = "1+-1i", num2 = "1+-1i"
+Output: "0+-2i"
+Explanation: (1 - i) * (1 - i) = 1 + i2 - 2 * i = -2i, and you need convert it to the form of 0+-2i.
+ 
+Constraints:
+num1 and num2 are valid complex numbers.
+*/
+
+class Solution {
+public:
+    string complexNumberMultiply(string a, string b) {
+        int r1 = stoi(a.substr(0, a.find('+')+1));
+        int r2 = stoi(b.substr(0, b.find('+')+1));
+        
+        int c1 = stoi(a.substr(a.find('+')+1));
+        int c2 = stoi(b.substr(b.find('+')+1));
+        
+        return to_string(r1*r2 - c1*c2) + "+" + to_string(r1*c2 + r2*c1) + "i";
+    }
+};

Diff for: Leetcode Daily Challenge/August-2021/README.md

@@ -24,5 +24,5 @@
 | 19. | [Maximum Product of Splitted Binary Tree](https://leetcode.com/explore/challenge/card/august-leetcoding-challenge-2021/615/week-3-august-15th-august-21st/3903/) | [cpp](./19.%20Maximum%20Product%20of%20Splitted%20Binary%20Tree.cpp) |
 | 20. | [Valid Sudoku](https://leetcode.com/explore/challenge/card/august-leetcoding-challenge-2021/615/week-3-august-15th-august-21st/3904/)                            |                  [cpp](./20.%20Valid%20Sudoku.cpp)                   |
 | 21. | [Sudoku Solver](https://leetcode.com/explore/challenge/card/august-leetcoding-challenge-2021/615/week-3-august-15th-august-21st/3905/)                            |                  [cpp](./20Sudoku%20Solver.%20.cpp)                   |
-| 23. | [Two Sum IV - Input is a BST](https://leetcode.com/explore/featured/card/august-leetcoding-challenge-2021/616/week-4-august-22nd-august-28th/3908/)                            |                  [cpp](./23Two%20Sum%20IV%20-%20Input%20is%20a%20BST.cpp)                   |
-| 24. | []()                            |                  [cpp](./24.cpp)                   |
+| 23. | [Two Sum IV - Input is a BST](https://leetcode.com/explore/featured/card/august-leetcoding-challenge-2021/616/week-4-august-22nd-august-28th/3908/)                            |                  [cpp](./23.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST.cpp)                   |
+| 24. | [Complex Number Multiplication](https://leetcode.com/explore/featured/card/august-leetcoding-challenge-2021/616/week-4-august-22nd-august-28th/3917/)                            |                  [cpp](./24.%20Complex%20Number%20Multiplication.cpp)                   |