day 32: 875-koko-eating-bananas

875-koko-eating-bananas/driver.cpp

@@ -0,0 +1,10 @@
+#include "soln.hpp"
+
+int main()
+{
+	vector<int> piles{30, 23, 11, 4, 20};
+	int h = 5, answer = 30;
+	Solution soln;
+	cout << "Found minimum k correctly? " << soln.test(piles, h, answer) << endl;
+	return 0;
+}

875-koko-eating-bananas/soln.cpp

@@ -0,0 +1,44 @@
+#include "soln.hpp"
+
+int Solution::minEatingSpeed(vector<int> &piles, int h)
+{
+	if (piles.size() < 2)
+	{
+		// cout << double(piles[0]/double(h)) << " " << ceil(piles[0]/double(h)) << endl;
+		return ceil(piles[0] / double(h));
+	}
+	long k_lmin = 0;
+	int k_max = 1;
+	int k_mid, hours_for_k_mid;
+	for (int pile : piles)
+	{
+		k_max = max(k_max, pile);
+		k_lmin += pile;
+	}
+	k_lmin /= h;
+	int k_min = k_lmin;
+	while (k_min < k_max)
+	{
+		k_mid = (k_min + k_max) / 2;
+		hours_for_k_mid = 0;
+		for (int pile : piles)
+		{
+			// cout << pile << " " << k_mid << endl;
+			hours_for_k_mid += ceil(pile / double(k_mid));
+		}
+		if (hours_for_k_mid > h)
+		{
+			k_min = k_mid + 1;
+		}
+		else
+		{
+			k_max = k_mid;
+		}
+	}
+	return k_min;
+}
+
+bool Solution::test(vector<int> &piles, int h, int answer)
+{
+	return minEatingSpeed(piles, h) == answer;
+}

875-koko-eating-bananas/soln.hpp

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