update

src/8/12/3sum.cpp

@@ -0,0 +1,47 @@
+#include <algorithm>
+#include <cstdint>
+#include <functional>
+#include <iostream>
+#include <map>
+#include <set>
+#include <tuple>
+#include <unordered_set>
+#include <vector>
+using namespace std;
+
+class Solution {
+public:
+    vector<vector<int>> threeSum(vector<int>& nums) {
+        vector<vector<int>> res;
+        set<vector<int>> s;
+        map<int,int> m;
+        for(int i=0;i<nums.size();i++){
+            m[nums[i]]++;
+        }
+        for(int i=0;i<nums.size();i++){
+            for(int j=i+1;j<nums.size();j++){
+                if(auto p =m.find(-(nums[i]+nums[j]));p!=m.end()){
+                    if(nums[i]==nums[j]){
+                        auto p = m.find(nums[i]);
+                        if(p->second>2)goto ok;
+                    }else{
+                        
+                    }
+                    continue;
+                    ok:;
+                    vector<int> nn={nums[i],nums[j],-(nums[i]+nums[j])};
+                    sort(nn.begin(),nn.end());
+                    if(s.find(nn)==s.end()){
+                        res.push_back(nn);
+                        s.insert(nn);
+                    }
+                }
+            }
+        }
+        return res;
+    }
+};
+
+int main(){
+
+}

src/8/12/group-anagrams.cpp

@@ -0,0 +1,15 @@
+#include<vector>
+#include<string>
+using namespace std;
+
+class Solution {
+public:
+    vector<vector<string>> groupAnagrams(vector<string>& strs) {
+        
+    }
+};
+
+
+int main(){
+
+}

src/8/12/trapping-rain-water.cpp

@@ -0,0 +1,34 @@
+#include <vector>
+using namespace std;
+
+class Solution {
+public:
+    int trap(std::vector<int> &height) {
+
+        if (height.size() < 3) {
+            return 0;
+        }
+        int n = height.size();
+        int l = 0, r = n - 1;
+
+        int lmax = 0;
+        int rmax = 0;
+
+        long long totw = 0;
+        while (l < r) {
+            lmax = std::max(lmax, height[l]);
+            rmax = std::max(rmax, height[r]);
+            if (lmax < rmax) {
+                totw += lmax - height[l];
+                l++;
+            } else {
+                totw += rmax - height[r];
+                r--;
+            }
+        }
+        return totw;
+    }
+};
+
+int main() {
+}