From 94bdecfc2eeab67d6657fb6c688478638a5b86fc Mon Sep 17 00:00:00 2001 From: dam <1782067308@qq.com> Date: Fri, 29 Nov 2024 15:56:34 +0800 Subject: [PATCH 1/2] =?UTF-8?q?=E6=B7=BB=E5=8A=A0474.=20=E4=B8=80=E5=92=8C?= =?UTF-8?q?=E9=9B=B6=20java=20=E4=B8=89=E7=BB=B4DP=E6=95=B0=E7=BB=84?= =?UTF-8?q?=E5=AE=9E=E7=8E=B0=E4=BB=A3=E7=A0=81?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0474.一和零.md | 65 +++++++++++++++++++++++++++++++++++++- 1 file changed, 64 insertions(+), 1 deletion(-) diff --git a/problems/0474.一和零.md b/problems/0474.一和零.md index e514e729..9d24f014 100644 --- a/problems/0474.一和零.md +++ b/problems/0474.一和零.md @@ -261,8 +261,70 @@ public: ## 其他语言版本 - ### Java + +三维DP数组实现 + +```java +class Solution { + public int findMaxForm(String[] strs, int m, int n) { + /// 数组有三个维度 + // 第一个维度:取前面的几个字符串 + // 第二个维度:0的数量限制(背包维度 1 容量) + // 第三个维度:1的数量限制(背包维度 2 容量) + int[][][] dpArr = new int[strs.length][m + 1][n + 1]; + + /// 初始化dpArr数组 + // 计算第一个字符串的零数量和1数量 + int zeroNum = 0; + int oneNum = 0; + for (char c : strs[0].toCharArray()) { + if (c == '0') { + zeroNum++; + } else { + oneNum++; + } + } + // 当0数量、1数量都容得下第一个字符串时,将DP数组的相应位置初始化为1,因为当前的子集数量为1 + for (int j = zeroNum; j <= m; j++) { + for (int k = oneNum; k <= n; k++) { + dpArr[0][j][k] = 1; + } + } + /// 依次填充加入第i个字符串之后的DP数组 + for (int i = 1; i < strs.length; i++) { + zeroNum = 0; + oneNum = 0; + for (char c : strs[i].toCharArray()) { + if (c == '0') { + zeroNum++; + } else { + oneNum++; + } + } + for (int j = 0; j <= m; j++) { + for (int k = 0; k <= n; k++) { + if (j >= zeroNum && k >= oneNum) { + // --if-- 当0数量维度和1数量维度的容量都大于等于当前字符串的0数量和1数量时,才考虑是否将当前字符串放入背包 + // 不放入第i个字符串,子集数量仍为 dpArr[i - 1][j][k] + // 放入第i个字符串,需要在0维度腾出 zeroNum 个容量,1维度腾出 oneNum 个容量,然后放入当前字符串,即 dpArr[i - 1][j - zeroNum][k - oneNum] + 1) + dpArr[i][j][k] = Math.max(dpArr[i - 1][j][k], dpArr[i - 1][j - zeroNum][k - oneNum] + 1); + } else { + // --if-- 无法放入第i个字符串,子集数量仍为 dpArr[i - 1][j][k] + dpArr[i][j][k] = dpArr[i - 1][j][k]; + } + } + } + } + return dpArr[dpArr.length - 1][m][n]; + } +} +``` + + + +二维DP数组实现 + ```Java class Solution { public int findMaxForm(String[] strs, int m, int n) { @@ -682,3 +744,4 @@ public class Solution + From c2e95f6c25b2c3f9ff61dc0891cc08360b676bb1 Mon Sep 17 00:00:00 2001 From: dam <1782067308@qq.com> Date: Sun, 26 Jan 2025 12:08:15 +0800 Subject: [PATCH 2/2] =?UTF-8?q?108=E5=86=97=E4=BD=99=E8=BF=9E=E6=8E=A5=20j?= =?UTF-8?q?ava=E5=AE=9E=E7=8E=B0?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/kamacoder/0108.冗余连接.md | 75 +++++++++++++++++++++++++ 1 file changed, 75 insertions(+) diff --git a/problems/kamacoder/0108.冗余连接.md b/problems/kamacoder/0108.冗余连接.md index efbbb6d2..df3dd4de 100644 --- a/problems/kamacoder/0108.冗余连接.md +++ b/problems/kamacoder/0108.冗余连接.md @@ -176,6 +176,81 @@ int main() { ### Java +```java +import java.util.Scanner; + +public class Main { + private static int[] father; + + public static void main(String[] args) { + Scanner scanner = new Scanner(System.in); + int pointNum = scanner.nextInt(); + father = new int[pointNum + 1]; + init(); + for (int i = 0; i < pointNum; i++) { + join(scanner.nextInt(), scanner.nextInt()); + } + } + + /** + * 并查集初始化 + */ + private static void init() { + for (int i = 1; i < father.length; i++) { + // 让每个元素指向自己 + father[i] = i; + } + } + + /** + * 并查集寻根 + * + * @param u + * @return + */ + private static int find(int u) { + // 判断 u 是否等于自己,如果是的话,直接返回自己 + // 如果不等于自己,就寻找根,寻找的时候,反复进行路径压缩 + return u == father[u] ? u : (father[u] = find(father[u])); + } + + /** + * 判断 u 和 v 是否同根 + * + * @param u + * @param v + * @return + */ + private static boolean isSame(int u, int v) { + return find(u) == find(v); + } + + /** + * 添加 边 到并查集,v 指向 u + * + * @param u + * @param v + */ + private static void join(int u, int v) { + // --if-- 如果两个点已经同根,说明他们的信息已经存储到并查集中了,直接返回即可 + // 寻找u的根 + int uRoot = find(u); + // 寻找v的根 + int vRoot = find(v); + if (uRoot == vRoot) { + // --if-- 如果u,v的根相同,说明两者已经连接了,直接输出 + System.out.println(u + " " + v); + return; + } + // --if-- 将信息添加到并查集 + father[vRoot] = uRoot; + } + +} +``` + + + ### Python ```python