day 19: 55-jump-game

55-jump-game/driver.cpp

@@ -0,0 +1,9 @@
+#include "soln.hpp"
+
+int main()	{
+	vector<int> nums = {3,2,1,0,4};
+	bool answer = false;
+	Solution soln;
+	cout << "Checked if can jump correctly? " << soln.test(nums, answer) << endl;
+	return 0;
+}

55-jump-game/soln.cpp

@@ -0,0 +1,32 @@
+#include "soln.hpp"
+
+bool Solution::canJump(vector<int> &nums)
+{
+	int n = nums.size();
+	int cur_pos = n - 2;
+	int gaps = 0;
+	int next_connect = n - 1;
+	// base cases
+	if (n == 1)
+		return true;
+	if (nums[0] == 0)
+		return false;
+	// track last known connection to get to end
+	while (cur_pos >= 0)
+	{
+		if (cur_pos + nums[cur_pos] >= next_connect)
+		{
+			gaps = 0;
+			next_connect = cur_pos;
+		}
+		else
+			gaps++;
+		cur_pos--;
+	}
+	return gaps == 0;
+}
+
+bool Solution::test(vector<int> &nums, bool answer)
+{
+	return canJump(nums) == answer;
+}

55-jump-game/soln.hpp

@@ -0,0 +1,7 @@
+#include <bits/stdc++.h>
+using namespace std;
+class Solution	{
+public:
+    bool canJump(vector<int>& nums);
+	bool test(vector<int>& nums, bool answer);
+};