#22 Got TLE, can not use DP

Tried using DP, but it not use full have to pose it like a search problem

2019Q1/cppWorkspace/leetcode740.cpp

@@ -0,0 +1,105 @@
+/*  Problem URL:    https://leetcode.com/problems/delete-and-earn/
+    Problem ID:     740
+    Issue ID:       22
+*/
+
+#include <iostream>
+#include <vector>
+#include <algorithm>
+#include <string>
+#include <sstream>
+#include <map>
+
+using namespace std;
+
+class Solution {
+private:
+    map<string,int> _cache;
+
+    string stringfy(const vector<int>& nums) {
+        stringstream ss;
+
+        for( const auto& num : nums ) {
+            ss << num << " ";
+        }
+
+        return ss.str();        
+    }
+
+    vector<int> getReducedList(const vector<int>& nums, int pickedNumber, size_t excludeIndex) {
+        vector<int> reducedList;
+
+        for( size_t i=0; i<nums.size(); i++ ) {
+            auto n { nums[i] };
+
+            // Don't add the number in that case
+            if( n == pickedNumber + 1 || n == pickedNumber - 1 || i == excludeIndex ) {
+                continue;
+            }
+
+            reducedList.emplace_back(n);
+        }
+
+        return reducedList;
+    }
+
+    int getMaxPoint(vector<int>& nums) {
+        size_t sz { nums.size() };
+
+        // base cases 
+        if( sz == 0 ) return 0;
+        else if( sz == 1 ) return nums[0];
+
+        // Representing the vector as string
+        string strRepresentation { stringfy(nums) };
+        vector<int> costs;
+
+        // DP table lookup
+        auto it = _cache.find(strRepresentation);
+        if( it != _cache.end() ) return it->second;
+
+        // Picking up one number, calulating the cost for the reduced list
+        for( size_t i=0; i<nums.size(); i++ ) {
+            auto number{ nums[i] };
+            auto rlist { getReducedList(nums, number, i) };
+            costs.emplace_back( number + getMaxPoint(rlist) );
+        }
+
+        // Adding to the DP table
+        auto maxCost { max_element(begin(costs), end(costs)) };
+        _cache.insert(make_pair(strRepresentation, *maxCost));
+
+        return *maxCost;
+    }
+
+public:
+    int deleteAndEarn(vector<int>& nums) {
+        // Preparing input for the main routine
+        sort(nums.begin(), nums.end());
+        _cache.clear();
+
+        return getMaxPoint(nums);
+    }
+};
+
+void testLeetcode740() {
+    Solution s;
+
+    vector<int> inp1{3,4,2};
+    vector<int> inp2{2,2,3,3,3,4};
+    vector<int> tleCase {1,8,5,9,6,9,4,1,7,3,3,6,3,3,8,2,6,3,2,2,1,2,9,8,7,1,1,10,6,7,3,9,6,10,5,4,10,1,6,7,4,7,4,1,9,5,1,5,7,5};
+
+    // Should output 6
+    cout << s.deleteAndEarn(inp1) << endl;
+
+    // Should output 9
+    cout << s.deleteAndEarn(inp2) << endl;
+
+    // Should not get TLE, correct output 138
+    cout << s.deleteAndEarn(tleCase) << endl;
+}
+
+int main() {
+    testLeetcode740();
+    return 0;
+}