Time: 14 ms (72.68%), Space: 7.9 MB (58.39%) - LeetHub

Author: JanaSabuj

largest-sum-of-averages/largest-sum-of-averages.cpp

@@ -0,0 +1,46 @@
+class Solution {    
+public:
+    double go_part(int idx, int n, int k, vector<int>& nums, vector<vector<double>>& cache) {
+        if(idx >= n)
+            return 0;
+        
+        if(cache[idx][k] != -1.0)
+            return cache[idx][k];
+        
+        if(k == 0) {
+            int sum = 0;
+            int cnt = 0;
+            
+            for(int i = idx; i < n; i++) {
+                sum += nums[i];
+                cnt++;
+            }
+            
+            double ans = (double)sum/cnt;            
+            return ans;
+        }
+        
+      
+        
+        double mx = 0.0;
+        double cum = 0;
+        int cnt = 0;
+        double avg = 0.0;
+
+        for(int i = idx; i < n; i++) {
+            cum += nums[i];
+            cnt++;
+            avg = (double) cum / cnt;
+            mx = max(mx, avg + go_part(i + 1, n, k - 1, nums, cache));
+        }                
+        
+        return cache[idx][k] = mx;
+    }
+
+    double largestSumOfAverages(vector<int>& nums, int k) {
+        int n = nums.size();                
+        vector<vector<double>> cache(n, vector<double>(k, -1.0));
+        double ans = go_part(0, n, k-1, nums, cache);               
+        return ans;
+    }    
+};