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Leetcode snippets
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| /* Binary search */ | |
| // find first element from the sorted list that is greater than certain number | |
| // e.g. find 3 from [2, 4, 5, 6, 9], ans should be the index of element 4 (first greater than) | |
| int find(vector<int>& nums, int target) { | |
| int left = 0, right = nums.size(); | |
| while (left < right) { | |
| int mid = left + (right - left) / 2; | |
| if (nums[mid] < target) left = mid + 1; | |
| else right = mid; | |
| } | |
| return right; | |
| } | |
| // find last element from the sorted list that is less than certain number | |
| // e.g. find 3 from [2, 4, 5, 6, 9], ans should be the index of element 2 (first greater than) | |
| int find(vector<int>& nums, int target) { | |
| int left = 0, right = nums.size(); | |
| while (left < right) { | |
| int mid = left + (right - left) / 2; | |
| if (nums[mid] < target) left = mid + 1; | |
| else right = mid; | |
| } | |
| return right - 1; | |
| } | |
| // Note: the only difference is the return value is right -> right - 1 | |
| /* LinkedList */ | |
| // note: 如果head在返回结果中变了，那么需要declare一个dummy | |
| // swap 0 1 and 3 4 | |
| // 0(pre) 1(curr) 3(temp) 4(temp->next) | |
| ListNode* temp = curr->next; | |
| curr->next = temp->next; // delete 3: 0 1 4 | |
| temp->next = pre->next; // 0 4 1 | |
| pre->next = temp; // 0(pre) 3(temp) 4(temp->next) 1(curr) | |
| pre = pre->next; // 0 3(pre, temp) 4(temp->next) 1(curr) | |
| // cycle in linked list, where does it start? | |
| // https://www.cnblogs.com/hiddenfox/p/3408931.html | |
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