坑爹的多数次过。。
1 class Solution { 2 public: 3 vector<int> twoSum(vector<int> &numbers, int target) { 4 // Start typing your C/C++ solution below 5 // DO NOT write int main() function 6 int left = 0; 7 int right = numbers.size() - 1; 8 vector<int> ret; 9 map<int, vector<int>> S; 10 for (int i = 0; i < numbers.size(); i++) S[numbers[i]].push_back(i+1); 11 sort(numbers.begin(), numbers.end()); 12 while (left < right) { 13 if (numbers[left] + numbers[right] == target) { 14 if (S[numbers[left]].size() > 1) { 15 ret.push_back(S[numbers[left]][0]); 16 ret.push_back(S[numbers[right]][1]); 17 return ret; 18 } 19 int a = S[numbers[left]][0]; 20 int b = S[numbers[right]][0]; 21 if (a > b) { 22 ret.push_back(b); 23 ret.push_back(a); 24 } 25 else { 26 ret.push_back(a); 27 ret.push_back(b); 28 } 29 return ret; 30 } 31 if (numbers[left] + numbers[right] < target) left++; 32 else right--; 33 } 34 } 35 };
后来写了另外一段代码，更清楚点
1 class Solution { 2 public: 3 vector<int> twoSum(vector<int> &numbers, int target) { 4 // Start typing your C/C++ solution below 5 // DO NOT write int main() function 6 map<int, int> S; 7 for (int i = 0; i < numbers.size(); i++) S[i+1] = numbers[i]; 8 sort(numbers.begin(), numbers.end()); 9 int left = 0; 10 int right = numbers.size()-1; 11 while (left < right) { 12 int sum = numbers[left] + numbers[right]; 13 if (sum == target) break; 14 if (sum < target) left++; 15 else right--; 16 } 17 vector<int> ret; 18 int first, second; 19 first = second = 0; 20 for (map<int, int>::iterator it = S.begin(); it != S.end(); it++) { 21 if (numbers[left] == it->second || numbers[right] == it->second) { 22 if (!first) first = it->first; 23 else second = it->first; 24 } 25 } 26 if (first > second) swap(first, second); 27 ret.push_back(first); 28 ret.push_back(second); 29 return ret; 30 } 31 };
C#
1 public class Solution { 2 public int[] TwoSum(int[] nums, int target) { 3 Dictionary<int, int> S = new Dictionary<int, int>(); 4 for (int i = 0; i < nums.Length; i++) S.Add(i+1, nums[i]); 5 Array.Sort(nums); 6 int left = 0, right = nums.Length-1; 7 while (left < right) { 8 int sum = nums[left] + nums[right]; 9 if (sum == target) break; 10 if (sum < target) left++; 11 else right--; 12 } 13 int[] ans = new int[2]; 14 int first = 0, second = 0; 15 foreach (var v in S) { 16 if (nums[left] == v.Value || nums[right] == v.Value) { 17 if (first == 0) first = v.Key; 18 else second = v.Key; 19 } 20 } 21 if (first > second) { 22 int tmp = first; 23 first = second; 24 second = tmp; 25 } 26 ans[0] = first; 27 ans[1] = second; 28 return ans; 29 } 30 }