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Add python codes and for the chapter of

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computational complexity.
Update Java codes.
Update Contributors.
This commit is contained in:
Yudong Jin
2022-11-25 20:12:20 +08:00
parent 83629f3d2c
commit daf25d5e64
17 changed files with 571 additions and 82 deletions
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11
codes/java/chapter_computational_complexity/leetcode_two_sum.java
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@ -8,9 +8,10 @@ package chapter_computational_complexity;
import java.util.*;
class solution_brute_force {
class SolutionBruteForce {
public int[] twoSum(int[] nums, int target) {
int size = nums.length;
// 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)
@ -21,10 +22,12 @@ class solution_brute_force {
}
}
class solution_hash_map {
class SolutionHashMap {
public int[] twoSum(int[] nums, int target) {
int size = nums.length;
// 辅助哈希表，空间复杂度 O(n)
Map<Integer, Integer> dic = new HashMap<>();
// 单层循环，时间复杂度 O(n)
for (int i = 0; i < size; i++) {
if (dic.containsKey(target - nums[i])) {
return new int[] { dic.get(target - nums[i]), i };
@ -43,11 +46,11 @@ public class leetcode_two_sum {
// ====== Driver Code ======
// 方法一
solution_brute_force slt1 = new solution_brute_force();
SolutionBruteForce slt1 = new SolutionBruteForce();
int[] res = slt1.twoSum(nums, target);
System.out.println(Arrays.toString(res));
// 方法二
solution_hash_map slt2 = new solution_hash_map();
SolutionHashMap slt2 = new SolutionHashMap();
res = slt2.twoSum(nums, target);
System.out.println(Arrays.toString(res));
}