algorithm/hello-algo
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Add build script for JS and TS codes.

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krahets
2023-02-08 19:45:06 +08:00
parent 22b7d65d20
commit 05f0054005
28 changed files with 227 additions and 2217 deletions
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56
codes/cpp/chapter_computational_complexity/leetcode_two_sum.cpp
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@ -7,38 +7,32 @@
#include "../include/include.hpp"
/* 方法一：暴力枚举 */
class SolutionBruteForce {
public:
vector<int> twoSum(vector<int>& nums, int target) {
int size = nums.size();
// 两层循环，时间复杂度 O(n^2)
for (int i = 0; i < size - 1; i++) {
for (int j = i + 1; j < size; j++) {
if (nums[i] + nums[j] == target)
return { i, j };
}
vector<int> twoSumBruteForce(vector<int>& nums, int target) {
int size = nums.size();
// 两层循环，时间复杂度 O(n^2)
for (int i = 0; i < size - 1; i++) {
for (int j = i + 1; j < size; j++) {
if (nums[i] + nums[j] == target)
return { i, j };
}
return {};
}
};
return {};
}
/* 方法二：辅助哈希表 */
class SolutionHashMap {
public:
vector<int> twoSum(vector<int>& nums, int target) {
int size = nums.size();
// 辅助哈希表，空间复杂度 O(n)
unordered_map<int, int> dic;
// 单层循环，时间复杂度 O(n)
for (int i = 0; i < size; i++) {
if (dic.find(target - nums[i]) != dic.end()) {
return { dic[target - nums[i]], i };
}
dic.emplace(nums[i], i);
vector<int> twoSumHashTable(vector<int>& nums, int target) {
int size = nums.size();
// 辅助哈希表，空间复杂度 O(n)
unordered_map<int, int> dic;
// 单层循环，时间复杂度 O(n)
for (int i = 0; i < size; i++) {
if (dic.find(target - nums[i]) != dic.end()) {
return { dic[target - nums[i]], i };
}
return {};
dic.emplace(nums[i], i);
}
};
return {};
}
int main() {
@ -48,19 +42,13 @@ int main() {
// ====== Driver Code ======
// 方法一
SolutionBruteForce* slt1 = new SolutionBruteForce();
vector<int> res = slt1->twoSum(nums, target);
vector<int> res = twoSumBruteForce(nums, target);
cout << "方法一 res = ";
PrintUtil::printVector(res);
// 方法二
SolutionHashMap* slt2 = new SolutionHashMap();
res = slt2->twoSum(nums, target);
res = twoSumHashTable(nums, target);
cout << "方法二 res = ";
PrintUtil::printVector(res);
// 释放内存
delete slt1;
delete slt2;
return 0;
}