File tree Expand file tree Collapse file tree 6 files changed +218
-8
lines changed
solution/2500-2599/2509.Cycle Length Queries in a Tree Expand file tree Collapse file tree 6 files changed +218
-8
lines changed Original file line number Diff line number Diff line change 7474
7575<!-- 这里可写通用的实现逻辑 -->
7676
77+ ** 方法一：求最近公共祖先**
78+
79+ 对于每次查询，我们找出 $a$, $b$ 两个节点的最近公共祖先，并且记录向上走的步数，那么此次查询的答案就是步数加一。
80+
81+ 求最近公共祖先时，如果 $a \gt b$，那么我们将 $a$ 往父节点移动；如果 $a \lt b$，我们将 $b$ 往其父节点移动。过程中累计步数，直至 $a = b$。
82+
83+ 时间复杂度 $O(n \times m)$。其中 $m$ 为数组 ` queries ` 的长度。
84+
7785<!-- tabs:start -->
7886
7987### ** Python3**
8088
8189<!-- 这里可写当前语言的特殊实现逻辑 -->
8290
8391``` python
84-
92+ class Solution :
93+ def cycleLengthQueries (self n : int , queries : List[List[int ]]) -> List[int ]:
94+ ans = []
95+ for a, b in queries:
96+ t = 1
97+ while a != b:
98+ if a > b:
99+ a >>= 1
100+ else :
101+ b >>= 1
102+ t += 1
103+ ans.append(t)
104+ return ans
85105```
86106
87107### ** Java**
88108
89109<!-- 这里可写当前语言的特殊实现逻辑 -->
90110
91111``` java
92-
112+ class Solution {
113+ public int [] cycleLengthQueries (int n , int [][] queries ) {
114+ int m = queries. length;
115+ int [] ans = new int [m];
116+ for (int i = 0 ; i < m; ++ i) {
117+ int a = queries[i][0 ], b = queries[i][1 ];
118+ int t = 1 ;
119+ while (a != b) {
120+ if (a > b) {
121+ a >> = 1 ;
122+ } else {
123+ b >> = 1 ;
124+ }
125+ ++ t;
126+ }
127+ ans[i] = t;
128+ }
129+ return ans;
130+ }
131+ }
93132```
94133
95134### ** C++**
96135
97136``` cpp
98-
137+ class Solution {
138+ public:
139+ vector<int > cycleLengthQueries(int n, vector<vector<int >>& queries) {
140+ vector<int > ans;
141+ for (auto& q : queries) {
142+ int a = q[ 0] , b = q[ 1] ;
143+ int t = 1;
144+ while (a != b) {
145+ if (a > b) {
146+ a >>= 1;
147+ } else {
148+ b >>= 1;
149+ }
150+ ++t;
151+ }
152+ ans.emplace_back(t);
153+ }
154+ return ans;
155+ }
156+ };
99157```
100158
101159### **Go**
102160
103161```go
104-
162+ func cycleLengthQueries(n int, queries [][]int) []int {
163+ ans := []int{}
164+ for _, q := range queries {
165+ a, b := q[0], q[1]
166+ t := 1
167+ for a != b {
168+ if a > b {
169+ a >>= 1
170+ } else {
171+ b >>= 1
172+ }
173+ t++
174+ }
175+ ans = append(ans, t)
176+ }
177+ return ans
178+ }
105179```
106180
107181### ** ...**
Original file line number Diff line number Diff line change 6969### ** Python3**
7070
7171``` python
72-
72+ class Solution :
73+ def cycleLengthQueries (self n : int , queries : List[List[int ]]) -> List[int ]:
74+ ans = []
75+ for a, b in queries:
76+ t = 1
77+ while a != b:
78+ if a > b:
79+ a >>= 1
80+ else :
81+ b >>= 1
82+ t += 1
83+ ans.append(t)
84+ return ans
7385```
7486
7587### ** Java**
7688
7789``` java
78-
90+ class Solution {
91+ public int [] cycleLengthQueries (int n , int [][] queries ) {
92+ int m = queries. length;
93+ int [] ans = new int [m];
94+ for (int i = 0 ; i < m; ++ i) {
95+ int a = queries[i][0 ], b = queries[i][1 ];
96+ int t = 1 ;
97+ while (a != b) {
98+ if (a > b) {
99+ a >> = 1 ;
100+ } else {
101+ b >> = 1 ;
102+ }
103+ ++ t;
104+ }
105+ ans[i] = t;
106+ }
107+ return ans;
108+ }
109+ }
79110```
80111
81112### ** C++**
82113
83114``` cpp
84-
115+ class Solution {
116+ public:
117+ vector<int > cycleLengthQueries(int n, vector<vector<int >>& queries) {
118+ vector<int > ans;
119+ for (auto& q : queries) {
120+ int a = q[ 0] , b = q[ 1] ;
121+ int t = 1;
122+ while (a != b) {
123+ if (a > b) {
124+ a >>= 1;
125+ } else {
126+ b >>= 1;
127+ }
128+ ++t;
129+ }
130+ ans.emplace_back(t);
131+ }
132+ return ans;
133+ }
134+ };
85135```
86136
87137### **Go**
88138
89139```go
90-
140+ func cycleLengthQueries(n int, queries [][]int) []int {
141+ ans := []int{}
142+ for _, q := range queries {
143+ a, b := q[0], q[1]
144+ t := 1
145+ for a != b {
146+ if a > b {
147+ a >>= 1
148+ } else {
149+ b >>= 1
150+ }
151+ t++
152+ }
153+ ans = append(ans, t)
154+ }
155+ return ans
156+ }
91157```
92158
93159### ** ...**
Original file line number Diff line number Diff line change 1+ class Solution {
2+ public:
3+ vector<int > cycleLengthQueries (int n, vector<vector<int >>& queries) {
4+ vector<int > ans;
5+ for (auto & q : queries) {
6+ int a = q[0 ], b = q[1 ];
7+ int t = 1 ;
8+ while (a != b) {
9+ if (a > b) {
10+ a >>= 1 ;
11+ } else {
12+ b >>= 1 ;
13+ }
14+ ++t;
15+ }
16+ ans.emplace_back (t);
17+ }
18+ return ans;
19+ }
20+ };
Original file line number Diff line number Diff line change 1+ func cycleLengthQueries (n int , queries [][]int ) []int {
2+ ans := []int {}
3+ for _ , q := range queries {
4+ a , b := q [0 ], q [1 ]
5+ t := 1
6+ for a != b {
7+ if a > b {
8+ a >>= 1
9+ } else {
10+ b >>= 1
11+ }
12+ t ++
13+ }
14+ ans = append (ans , t )
15+ }
16+ return ans
17+ }
Original file line number Diff line number Diff line change 1+ class Solution {
2+ public int [] cycleLengthQueries (int n , int [][] queries ) {
3+ int m = queries .length ;
4+ int [] ans = new int [m ];
5+ for (int i = 0 ; i < m ; ++i ) {
6+ int a = queries [i ][0 ], b = queries [i ][1 ];
7+ int t = 1 ;
8+ while (a != b ) {
9+ if (a > b ) {
10+ a >>= 1 ;
11+ } else {
12+ b >>= 1 ;
13+ }
14+ ++t ;
15+ }
16+ ans [i ] = t ;
17+ }
18+ return ans ;
19+ }
20+ }
Original file line number Diff line number Diff line change 1+ class Solution :
2+ def cycleLengthQueries (self , n : int , queries : List [List [int ]]) -> List [int ]:
3+ ans = []
4+ for a , b in queries :
5+ t = 1
6+ while a != b :
7+ if a > b :
8+ a >>= 1
9+ else :
10+ b >>= 1
11+ t += 1
12+ ans .append (t )
13+ return ans
You can’t perform that action at this time.
0 commit comments