day 29: 22-generate-parentheses, 739-daily-temperatures

22-generate-parentheses/driver.cpp

@@ -0,0 +1,12 @@
+#include "soln.hpp"
+
+int main()
+{
+	int n = 4;
+	Solution soln;
+	vector<string> result = soln.generateParenthesis(n);
+	for (string str : result)
+		cout << str << "\t";
+	cout << endl;
+	return 0;
+}

22-generate-parentheses/soln.cpp

@@ -0,0 +1,24 @@
+#include "soln.hpp"
+
+void Solution::recurseParenthesis(vector<string> &result, string str, int left, int right)
+{
+	// base case
+	if (left == 0 & right == 0)
+	{
+		result.push_back(str);
+		return;
+	}
+	// opening parenthesis can be added, so add
+	if (left > 0)
+		recurseParenthesis(result, str + "(", left - 1, right);
+	// closing parenthesis can be added, so add
+	if (right > left)
+		recurseParenthesis(result, str + ")", left, right - 1);
+}
+
+vector<string> Solution::generateParenthesis(int n)
+{
+	vector<string> result;
+	recurseParenthesis(result, "", n, n);
+	return result;
+}

22-generate-parentheses/soln.hpp

@@ -0,0 +1,8 @@
+#include <bits/stdc++.h>
+using namespace std;
+class Solution
+{
+public:
+    void recurseParenthesis(vector<string>& result, string str, int left, int right);
+    vector<string> generateParenthesis(int n);
+};

739-daily-temperatures/driver.cpp

@@ -0,0 +1,10 @@
+#include "soln.hpp"
+
+int main()
+{
+	vector<int> temps{73, 74, 75, 71, 69, 72, 76, 73};
+	vector<int> answer{1, 1, 4, 2, 1, 1, 0, 0};
+	Solution soln;
+	cout << "Found next warmer days correctly? " << soln.test(temps, answer) << endl;
+	return 0;
+}

739-daily-temperatures/soln.cpp

@@ -0,0 +1,44 @@
+#include "soln.hpp"
+
+vector<int> Solution::dailyTemperatures(vector<int> &temperatures)
+{
+	// brute force
+	// vector<int> answer(temperatures.size());
+	// for(int i = 0; i < temperatures.size(); i++)    {
+	//     bool warmer_day_found = false;
+	//     for(int j = i+1; j < temperatures.size(); j++)  {
+	//         if(temperatures[j] > temperatures[i])   {
+	//             warmer_day_found = true;
+	//             answer[i] = j-i;
+	//             break;
+	//         }
+	//     }
+	//     if(!warmer_day_found)
+	//         answer[i] = 0;
+	// }
+	// return answer;
+
+	// stack, neetcode
+	vector<int> answer(temperatures.size());
+	stack<int> dec_temps;
+	for (int i = 0; i < temperatures.size(); i++)
+	{
+		while (!dec_temps.empty() && temperatures[i] > temperatures[dec_temps.top()])
+		{
+			answer[dec_temps.top()] = i - dec_temps.top();
+			dec_temps.pop();
+		}
+		dec_temps.push(i);
+	}
+	while (!dec_temps.empty())
+	{
+		answer[dec_temps.top()] = 0;
+		dec_temps.pop();
+	}
+	return answer;
+}
+
+bool Solution::test(vector<int> &temperatures, vector<int> &answer)
+{
+	return dailyTemperatures(temperatures) == answer;
+}

739-daily-temperatures/soln.hpp

@@ -0,0 +1,8 @@
+#include <bits/stdc++.h>
+using namespace std;
+class Solution
+{
+public:
+	vector<int> dailyTemperatures(vector<int> &temperatures);
+	bool test(vector<int> &temperatures, vector<int> &answer);
+};