CSES - Aalto Competitive Programming 2024 - wk7 Homework - Results
Submission details
Task:Download Speed
Sender:laluj
Submission time:2024-10-22 22:41:23 +0300
Language:C++ (C++17)
Status:READY
Result:
Test results
testverdicttime
#1ACCEPTED0.00 sdetails
#2ACCEPTED0.00 sdetails
#3ACCEPTED0.00 sdetails
#4ACCEPTED0.00 sdetails
#50.01 sdetails
#6ACCEPTED0.01 sdetails
#7ACCEPTED0.01 sdetails
#8ACCEPTED0.00 sdetails
#9ACCEPTED0.00 sdetails
#10ACCEPTED0.00 sdetails
#110.01 sdetails
#120.00 sdetails

Code

#include <bits/stdc++.h>

using namespace std;

#define debug(x) cerr << #x << ": " << x << endl;
#define ll long long
#define ull unsigned long long
#define vi vector<int>


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

using namespace std;

struct Edge {
    int to;
    ull capacity;
    ull flow; 
    int rev;
};

class MaxFlow {
public:
    MaxFlow(int n) : n(n) {
        adj.resize(n);
    }

    void add_edge(int u, int v, ull capacity) {
        Edge a = {v, capacity, 0, (int)adj[v].size()};
        Edge b = {u, 0, 0, (int)adj[u].size()};
        adj[u].push_back(a);
        adj[v].push_back(b);
    }

    int max_flow(int s, int t) {
        ull total_flow = 0;

        while (true) {
            vector<int> parent(n, -1);
            vector<int> edge_index(n, -1);
            queue<int> q;
            q.push(s);
            parent[s] = s;

            while (!q.empty() && parent[t] == -1) {
                int u = q.front();
                q.pop();

                for (int i = 0; i < (int) adj[u].size(); i++) {
                    Edge &e = adj[u][i];
                    if (parent[e.to] == -1 && e.capacity > e.flow) {
                        parent[e.to] = u;
                        edge_index[e.to] = i;
                        q.push(e.to);
                    }
                }
            }

            if (parent[t] == -1)
                break;

            ull aug_flow = ULLONG_MAX;
            for (int v = t; v != s; v = parent[v]) {
                int u = parent[v];
                int idx = edge_index[v];
                aug_flow = min(aug_flow, adj[u][idx].capacity - adj[u][idx].flow);
            }

            for (int v = t; v != s; v = parent[v]) {
                int u = parent[v];
                int idx = edge_index[v];
                adj[u][idx].flow += aug_flow;
                adj[v][adj[u][idx].rev].flow -= aug_flow;
            }

            total_flow += aug_flow;
        }

        return total_flow;
    }

private:
    int n;
    vector<vector<Edge>> adj;
};

int main() {
    int n, m;
    cin >> n >> m;

    MaxFlow maxFlow(n);
    int a, b; ull c;
    for (int i = 0; i < m; i++) {
        cin >> a >> b >> c; a--; b--;
        maxFlow.add_edge(a, b, c);
    }

    cout << maxFlow.max_flow(0, n - 1) << endl;

    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:

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

correct output
1000000000000

user output
-727379968

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:

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

correct output
111000000000

user output
-669149696

Test 12

Verdict:

input
7 9
1 2 1
1 3 1
1 4 1
2 5 1
...

correct output
2

user output
1