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Retranslate the complete English edition from Simplified Chinese (#2010)

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* Retranslate the complete English edition from Simplified Chinese

* Polish three English explanations after reader-focused review
This commit is contained in:
Yudong Jin
2026-10-31 03:35:51 +08:00
committed by GitHub
parent ef46e2ed95
commit 14c314c08c
1502 changed files with 29459 additions and 23517 deletions
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28
en/codes/java/chapter_backtracking/subset_sum_ii.java
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@@ -9,31 +9,31 @@ package chapter_backtracking;
import java.util.*;
public class subset_sum_ii {
/* Backtracking algorithm: Subset sum II */
/* Backtracking: subset sum II */
static void backtrack(List<Integer> state, int target, int[] choices, int start, List<List<Integer>> res) {
// When the subset sum equals target, record the solution
// Record a solution when the remaining target is zero, so the subset sums to the original target
if (target == 0) {
res.add(new ArrayList<>(state));
return;
}
// Traverse all choices
// Pruning 2: start traversing from start to avoid generating duplicate subsets
// Pruning 3: start traversing from start to avoid repeatedly selecting the same element
// Iterate over all choices
// Pruning 2: iterate from start to avoid generating duplicate subsets
// Pruning 3: iterate from start to avoid choosing the same element again
for (int i = start; i < choices.length; i++) {
// Pruning 1: if the subset sum exceeds target, end the loop directly
// This is because the array is sorted, and later elements are larger, so the subset sum will definitely exceed target
// Pruning 1: exit the loop if the next element exceeds the remaining target
// The array is sorted, so later elements are at least as large and also exceed the remaining target
if (target - choices[i] < 0) {
break;
}
// Pruning 4: if this element equals the left element, it means this search branch is duplicate, skip it directly
// Pruning 4: if this element equals its left neighbor at the same search depth, the branch is a duplicate; skip it
if (i > start && choices[i] == choices[i - 1]) {
continue;
}
// Attempt: make choice, update target, start
// Try: make a choice and update target and start
state.add(choices[i]);
// Proceed to the next round of selection
// Proceed to the next choice
backtrack(state, target - choices[i], choices, i + 1, res);
// Backtrack: undo choice, restore to previous state
// Backtrack: undo the choice and restore the previous state
state.remove(state.size() - 1);
}
}
@@ -42,8 +42,8 @@ public class subset_sum_ii {
static List<List<Integer>> subsetSumII(int[] nums, int target) {
List<Integer> state = new ArrayList<>(); // State (subset)
Arrays.sort(nums); // Sort nums
int start = 0; // Start point for traversal
List<List<Integer>> res = new ArrayList<>(); // Result list (subset list)
int start = 0; // Starting index for iteration
List<List<Integer>> res = new ArrayList<>(); // Result list (list of subsets)
backtrack(state, target, nums, start, res);
return res;
}
@@ -55,6 +55,6 @@ public class subset_sum_ii {
List<List<Integer>> res = subsetSumII(nums, target);
System.out.println("Input array nums = " + Arrays.toString(nums) + ", target = " + target);
System.out.println("All subsets with sum equal to " + target + " are res = " + res);
System.out.println("All subsets with sum " + target + " : res = " + res);
}
}