Struggled to complete 3 sum closest

LibStudySesh.vcxproj

@@ -127,11 +127,13 @@
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
-    <ClCompile Include="src\leet.cpp" />
+    <ClCompile Include="src\3sum.cpp" />
+    <ClCompile Include="src\3sumclosest.cpp" />
     <ClCompile Include="src\main.cpp" />
   </ItemGroup>
   <ItemGroup>
-    <ClInclude Include="src\leet.h" />
+    <ClInclude Include="src\3sum.h" />
+    <ClInclude Include="src\3sumclosest.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">

LibStudySesh.vcxproj.filters

@@ -18,12 +18,18 @@
     <ClCompile Include="src\main.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
-    <ClCompile Include="src\leet.cpp">
+    <ClCompile Include="src\3sum.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="src\3sumclosest.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
   </ItemGroup>
   <ItemGroup>
-    <ClInclude Include="src\leet.h">
+    <ClInclude Include="src\3sum.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="src\3sumclosest.h">
       <Filter>Header Files</Filter>
     </ClInclude>
   </ItemGroup>

src/3sum.cpp

@@ -1,5 +1,5 @@
 #pragma once
-#include "leet.h"
+#include "3sum.h"
 
 std::vector<std::vector<int>> Solution::threeSum(std::vector<int>& nums) {
 	std::vector<std::vector<int>> ans;

src/3sumclosest.cpp

@@ -0,0 +1,40 @@
+#include "3sumclosest.h"
+
+int Solution::threeSumClosest(std::vector<int>& nums, int target) {
+	std::unordered_map<int, int> map;
+
+	int ans = INT_MAX;
+
+	std::sort(nums.begin(), nums.end());
+
+	for (int i = 0; i < nums.size(); i++)
+		map[nums[i]] = i;
+
+	for (int i = 0; i < nums.size(); i++)
+	{
+		for (int j = i + 1; j < nums.size(); j++)
+		{
+			int required = (target - (nums[i] + nums[j])) * -1;
+
+			if (map.count(required))
+				return nums[i] + nums[j] + required;
+
+			//Find closest alternative
+			int index = j+1;
+			int current = nums[j+1];
+			while (gettingCloser(required, nums[++index], current)) {
+				current = nums[index];
+			}
+
+			//See if closest alternative is closer
+			if (std::abs(required - current) < std::abs(target - ans))
+				ans = current + nums[i] + nums[j];
+		}
+	}
+
+	return ans;
+}
+
+bool Solution::gettingCloser(int target, int newVal, int current) {
+	return std::abs(target - newVal) < std::abs(target - current);
+}

src/3sumclosest.h

@@ -0,0 +1,10 @@
+#pragma once
+#include <algorithm>
+#include <vector>
+#include <unordered_map>
+
+class Solution {
+public:
+    int threeSumClosest(std::vector<int>& nums, int target);
+    bool gettingCloser(int target, int newVal, int current);
+};