Submission details
Task:Download Speed
Sender:ind1f
Submission time:2025-10-10 00:04:47 +0300
Language:C++ (C++17)
Status:READY
Result:ACCEPTED
Test results
testverdicttime
#1ACCEPTED0.00 sdetails
#2ACCEPTED0.00 sdetails
#3ACCEPTED0.00 sdetails
#4ACCEPTED0.00 sdetails
#5ACCEPTED0.00 sdetails
#6ACCEPTED0.01 sdetails
#7ACCEPTED0.01 sdetails
#8ACCEPTED0.00 sdetails
#9ACCEPTED0.00 sdetails
#10ACCEPTED0.01 sdetails
#11ACCEPTED0.00 sdetails
#12ACCEPTED0.00 sdetails

Compiler report

input/code.cpp:9:24: warning: overflow in conversion from 'double' to 'int' changes value from '1.0e+18' to '2147483647' [-Woverflow]
    9 | const int LLINF = 1e18 + 10;
      |                   ~~~~~^~~~
input/code.cpp: In function 'long long int max_flow(int, int)':
input/code.cpp:42:19: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   42 |   while (tmp_flow = find_flow(s, t)) {
      |          ~~~~~~~~~^~~~~~~~~~~~~~~~~

Code

#include <iostream>
#include <vector>
#include <queue>
#include <cstring>

using namespace std;

const int N = 5e2 + 5;
const int LLINF = 1e18 + 10;

int n, m;
long long cap[N][N];
vector<int> g[N];
int p[N];

long long find_flow(int s, int t) {
  memset(p, -1, sizeof(p));
  queue<pair<int, long long> > q;
  q.push(pair<int, long long>(s, LLINF));
  p[s] = -2;
  while (!q.empty()) {
    int u = q.front().first;
    long long flow = q.front().second;
    q.pop();
    for (int v : g[u]) {
      if (p[v] == -1 && cap[u][v] > 0) {
        p[v] = u;
        long long new_flow = min(flow, cap[u][v]);
        if (v == t) {
          return new_flow;
        }
        q.push(pair<int, long long>(v, new_flow));
      }
    }
  }
  return 0;
}

long long max_flow(int s, int t) {
  long long flow = 0;
  long long tmp_flow; 
  while (tmp_flow = find_flow(s, t)) {
    flow += tmp_flow;
    int y = t;
    while (y != s) {
      int x = p[y];
      cap[x][y] -= tmp_flow;
      cap[y][x] += tmp_flow;
      y = p[y];
    }
  }
  return flow;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> m;
  while (m--) {
    int a, b, c;
    cin >> a >> b >> c;
    cap[a][b] += c;
    g[a].emplace_back(b);
    g[b].emplace_back(a);
  }
  cout << (1 == n ? 0 : max_flow(1, n)) << '\n';
  return 0;
}

Test details

Test 1

Verdict: ACCEPTED

input
4 3
1 2 5
2 3 3
3 4 6

correct output
3

user output
3

Test 2

Verdict: ACCEPTED

input
4 5
1 2 1
1 3 1
2 3 1
2 4 1
...

correct output
2

user output
2

Test 3

Verdict: ACCEPTED

input
4 5
1 2 1000000000
1 3 1000000000
2 3 1
2 4 1000000000
...

correct output
2000000000

user output
2000000000

Test 4

Verdict: ACCEPTED

input
2 1
2 1 100

correct output
0

user output
0

Test 5

Verdict: ACCEPTED

input
2 1000
1 2 1000000000
1 2 1000000000
1 2 1000000000
1 2 1000000000
...

correct output
1000000000000

user output
1000000000000

Test 6

Verdict: ACCEPTED

input
500 998
1 2 54
1 3 59
1 4 83
2 5 79
...

correct output
60

user output
60

Test 7

Verdict: ACCEPTED

input
500 998
1 2 530873053
1 3 156306296
1 4 478040476
3 5 303609600
...

correct output
1093765123

user output
1093765123

Test 8

Verdict: ACCEPTED

input
2 1
1 2 1

correct output
1

user output
1

Test 9

Verdict: ACCEPTED

input
4 5
1 2 3
2 4 2
1 3 4
3 4 5
...

correct output
6

user output
6

Test 10

Verdict: ACCEPTED

input
4 5
1 2 1
1 3 2
3 2 1
2 4 2
...

correct output
3

user output
3

Test 11

Verdict: ACCEPTED

input
10 999
1 2 1000000000
1 2 1000000000
1 2 1000000000
1 2 1000000000
...

correct output
111000000000

user output
111000000000

Test 12

Verdict: ACCEPTED

input
7 9
1 2 1
1 3 1
1 4 1
2 5 1
...

correct output
2

user output
2