字符串转换完成

三数之和待优化

.gitignore

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+#仅保留代码文件
+*
+!.gitignore
+!*.java
+!*.py
+!*.cpp
+!*.c
+!*.go
+!*.js

myAtoi.cpp

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+#include <iostream>
+#include <math.h>
+#include <memory>
+#include <string>
+
+using namespace std;
+
+string test = "-91283472332";
+
+class Solution
+{
+public:
+    int myAtoi(string s)
+    {
+        auto i = s.begin();
+        long long toReturn = 0;
+        while (*i == ' ') {
+            i++;
+        }
+        auto head = i;
+        i++;
+        while ((('0' <= *i) and (*i <= '9'))) {
+            i++;
+        }
+        auto end = i++;
+        i = head;
+        if ((('0' <= *i) and (*i <= '9')) or (*i == '-')) {
+            while ('0' <= *i <= '9') {
+                i++;
+                if (i == end) {
+                    break;
+                }
+            }
+            i--;
+            long long carry = 0;
+            while (i != head) {
+                toReturn += pow(10, carry) * ((*i) - 48);
+                i--;
+                carry++;
+            }
+            if (*i == '-') {
+                return -toReturn;
+            } else {
+                return toReturn + pow(10, carry) * ((*i) - 48);
+            }
+        } else {
+            return 0;
+        }
+    }
+};
+
+int main()
+{
+    Solution s;
+    cout << s.myAtoi(test) << endl;
+    return 0;
+}

threeSum.cpp

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+#include <algorithm>
+#include <iostream>
+#include <set>
+#include <vector>
+using namespace std;
+
+class Solution
+{
+public:
+    vector<vector<int>> threeSum(vector<int> &nums)
+    {
+
+        sort(nums.begin(), nums.end());
+        set<vector<int>> res;
+
+        for(int i = 0; i < nums.size(); i++) {
+            for(int j = i + 1; j < nums.size(); j++) {
+                for(int k = nums.size() - 1; k > j ; k--) {
+                    if(nums[i] + nums[j] + nums[k] == 0) {
+                        vector<int> tmp = {nums[i], nums[j], nums[k]};
+                        res.insert(tmp);
+                    }
+                    
+                }
+            }
+        }
+
+        return vector<vector<int>>(res.begin(), res.end());
+    }
+};
+
+int main()
+{
+    Solution s;
+    vector<int> nums = {-1, 0, 1, 2, -1, -4};
+    vector<vector<int>> res = s.threeSum(nums);
+    for(auto &v : res) {
+        for(auto &i : v) {
+            cout << i << " ";
+        }
+        cout << endl;
+    }
+
+    return 0;
+}