Skip to content

Commit 1944b38

Browse files
yanglbmeyanglbme
authored
feat: add solutions to lc problem: No.1601 (doocs#2543)
No.1601.Maximum Number of Achievable Transfer Requests
1 parent 5812f34 commit 1944b38

File tree

4 files changed

+151
-4
lines changed

4 files changed

+151
-4
lines changed

‎solution/1600-1699/1601.Maximum Number of Achievable Transfer Requests/README.md

+49-1
Original file line numberDiff line numberDiff line change
@@ -201,7 +201,7 @@ function maximumRequests(n: number, requests: number[][]): number {
201201
const m = requests.length;
202202
let ans = 0;
203203
const check = (mask: number): boolean => {
204-
const cnt = new Array(n).fill(0);
204+
const cnt = Array(n).fill(0);
205205
for (let i = 0; i < m; ++i) {
206206
if ((mask >> i) & 1) {
207207
const [f, t] = requests[i];
@@ -269,6 +269,54 @@ function bitCount(i) {
269269
}
270270
```
271271

272+
```cs
273+
public class Solution {
274+
private int m;
275+
private int n;
276+
private int[][] requests;
277+
278+
public int MaximumRequests(int n, int[][] requests) {
279+
m = requests.Length;
280+
this.n = n;
281+
this.requests = requests;
282+
int ans = 0;
283+
for (int mask = 0; mask < (1 << m); ++mask) {
284+
int cnt = CountBits(mask);
285+
if (ans < cnt && Check(mask)) {
286+
ans = cnt;
287+
}
288+
}
289+
return ans;
290+
}
291+
292+
private bool Check(int mask) {
293+
int[] cnt = new int[n];
294+
for (int i = 0; i < m; ++i) {
295+
if (((mask >> i) & 1) == 1) {
296+
int f = requests[i][0], t = requests[i][1];
297+
--cnt[f];
298+
++cnt[t];
299+
}
300+
}
301+
foreach (int v in cnt) {
302+
if (v != 0) {
303+
return false;
304+
}
305+
}
306+
return true;
307+
}
308+
309+
private int CountBits(int n) {
310+
int count = 0;
311+
while (n > 0) {
312+
n -= n & -n;
313+
++count;
314+
}
315+
return count;
316+
}
317+
}
318+
```
319+
272320
<!-- tabs:end -->
273321

274322
<!-- end -->

‎solution/1600-1699/1601.Maximum Number of Achievable Transfer Requests/README_EN.md

+56-2
Original file line numberDiff line numberDiff line change
@@ -60,7 +60,13 @@ We can achieve all the requests. </pre>
6060

6161
## Solutions
6262

63-
### Solution 1
63+
### Solution 1: Binary Enumeration
64+
65+
We note that the length of the room change request list does not exceed $16$. Therefore, we can use the method of binary enumeration to enumerate all room change request lists. Specifically, we can use a binary number of length $16$ to represent a room change request list, where the $i$-th bit being $1$ means the $i$-th room change request is selected, and $0$ means the $i$-th room change request is not selected.
66+
67+
We enumerate all binary numbers in the range of $[1, 2^{m})$, for each binary number $mask$, we first calculate how many $1$s are in its binary representation, denoted as $cnt$. If $cnt$ is larger than the current answer $ans$, then we judge whether $mask$ is a feasible room change request list. If it is, then we update the answer $ans$ with $cnt$. To judge whether $mask$ is a feasible room change request list, we only need to check whether the net inflow of each room is $0$.
68+
69+
The time complexity is $O(2^m \times (m + n))$, and the space complexity is $O(n)$, where $m$ and $n$ are the lengths of the room change request list and the number of rooms, respectively.
6470

6571
<!-- tabs:start -->
6672

@@ -190,7 +196,7 @@ function maximumRequests(n: number, requests: number[][]): number {
190196
const m = requests.length;
191197
let ans = 0;
192198
const check = (mask: number): boolean => {
193-
const cnt = new Array(n).fill(0);
199+
const cnt = Array(n).fill(0);
194200
for (let i = 0; i < m; ++i) {
195201
if ((mask >> i) & 1) {
196202
const [f, t] = requests[i];
@@ -258,6 +264,54 @@ function bitCount(i) {
258264
}
259265
```
260266

267+
```cs
268+
public class Solution {
269+
private int m;
270+
private int n;
271+
private int[][] requests;
272+
273+
public int MaximumRequests(int n, int[][] requests) {
274+
m = requests.Length;
275+
this.n = n;
276+
this.requests = requests;
277+
int ans = 0;
278+
for (int mask = 0; mask < (1 << m); ++mask) {
279+
int cnt = CountBits(mask);
280+
if (ans < cnt && Check(mask)) {
281+
ans = cnt;
282+
}
283+
}
284+
return ans;
285+
}
286+
287+
private bool Check(int mask) {
288+
int[] cnt = new int[n];
289+
for (int i = 0; i < m; ++i) {
290+
if (((mask >> i) & 1) == 1) {
291+
int f = requests[i][0], t = requests[i][1];
292+
--cnt[f];
293+
++cnt[t];
294+
}
295+
}
296+
foreach (int v in cnt) {
297+
if (v != 0) {
298+
return false;
299+
}
300+
}
301+
return true;
302+
}
303+
304+
private int CountBits(int n) {
305+
int count = 0;
306+
while (n > 0) {
307+
n -= n & -n;
308+
++count;
309+
}
310+
return count;
311+
}
312+
}
313+
```
314+
261315
<!-- tabs:end -->
262316

263317
<!-- end -->

‎solution/1600-1699/1601.Maximum Number of Achievable Transfer Requests/Solution.cs

+45
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,45 @@
1+
public class Solution {
2+
private int m;
3+
private int n;
4+
private int[][] requests;
5+
6+
public int MaximumRequests(int n, int[][] requests) {
7+
m = requests.Length;
8+
this.n = n;
9+
this.requests = requests;
10+
int ans = 0;
11+
for (int mask = 0; mask < (1 << m); ++mask) {
12+
int cnt = CountBits(mask);
13+
if (ans < cnt && Check(mask)) {
14+
ans = cnt;
15+
}
16+
}
17+
return ans;
18+
}
19+
20+
private bool Check(int mask) {
21+
int[] cnt = new int[n];
22+
for (int i = 0; i < m; ++i) {
23+
if (((mask >> i) & 1) == 1) {
24+
int f = requests[i][0], t = requests[i][1];
25+
--cnt[f];
26+
++cnt[t];
27+
}
28+
}
29+
foreach (int v in cnt) {
30+
if (v != 0) {
31+
return false;
32+
}
33+
}
34+
return true;
35+
}
36+
37+
private int CountBits(int n) {
38+
int count = 0;
39+
while (n > 0) {
40+
n -= n & -n;
41+
++count;
42+
}
43+
return count;
44+
}
45+
}

‎solution/1600-1699/1601.Maximum Number of Achievable Transfer Requests/Solution.ts

+1-1
Original file line numberDiff line numberDiff line change
@@ -2,7 +2,7 @@ function maximumRequests(n: number, requests: number[][]): number {
22
const m = requests.length;
33
let ans = 0;
44
const check = (mask: number): boolean => {
5-
const cnt = new Array(n).fill(0);
5+
const cnt = Array(n).fill(0);
66
for (let i = 0; i < m; ++i) {
77
if ((mask >> i) & 1) {
88
const [f, t] = requests[i];

0 commit comments

Comments
 (0)