diff --git a/problems/1971.寻找图中是否存在路径.md b/problems/1971.寻找图中是否存在路径.md index 132b0181..89a2a1fe 100644 --- a/problems/1971.寻找图中是否存在路径.md +++ b/problems/1971.寻找图中是否存在路径.md @@ -284,6 +284,48 @@ var validPath = function(n, edges, source, destination) { }; ``` +### Go + +```go +func validPath(n int, edges [][]int, source int, destination int) bool { + n = 200005 + father := make([]int, n) + // 并查集初始化 + for i := 0; i < n; i++ { + father[i] = i + } + + var find func(u int) int // 并查集里寻根的过程 + find = func(u int) int { + // 如果根就是自己,直接返回 + // 如果根不是自己,就根据数组下标一层一层向下找 + if u == father[u] { + return u + } + return find(father[u]) + } + + var join func(u, v int) // 将 v->u 这条边加入并查集 + join = func(u, v int) { + u = find(u) + v = find(v) + if u == v { + return + } + father[v] = u + } + + for i := 0; i < len(edges); i++ { + join(edges[i][0], edges[i][1]) + } + + source = find(source) + destination = find(destination) + return source == destination +} + +``` +

diff --git a/problems/kama54.替换数字.md b/problems/kama54.替换数字.md index f03e575d..7dc22c0a 100644 --- a/problems/kama54.替换数字.md +++ b/problems/kama54.替换数字.md @@ -142,7 +142,7 @@ for (int i = 0; i < a.size(); i++) { ### C: ### Java: - +解法一 ```java import java.util.Scanner; @@ -160,6 +160,42 @@ class Main { } } ``` +解法二 +```java +// 为了还原题目本意,先把原数组复制到扩展长度后的新数组,然后不再使用原数组、原地对新数组进行操作。 +import java.util.*; + +public class Main { + public static void main(String[] args) { + Scanner sc = new Scanner(System.in); + String s = sc.next(); + int len = s.length(); + for (int i = 0; i < s.length(); i++) { + if (s.charAt(i) >= 0 && s.charAt(i) <= '9') { + len += 5; + } + } + + char[] ret = new char[len]; + for (int i = 0; i < s.length(); i++) { + ret[i] = s.charAt(i); + } + for (int i = s.length() - 1, j = len - 1; i >= 0; i--) { + if ('0' <= ret[i] && ret[i] <= '9') { + ret[j--] = 'r'; + ret[j--] = 'e'; + ret[j--] = 'b'; + ret[j--] = 'm'; + ret[j--] = 'u'; + ret[j--] = 'n'; + } else { + ret[j--] = ret[i]; + } + } + System.out.println(ret); + } +} +``` ### Go: ````go