Distinct Routes

#include<bits/stdc++.h>
//#include<unordered_set>
#pragma GCC optimize("Ofast")
using namespace std;
#define int long long
#define die(x) return cout << x << endl, 0
#define FI first
#define SE second
#define all(o) o.begin(), o.end()
#define endl '\n'
#define IOS ios::sync_with_stdio(0), cin.tie(0)
#define FILE freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#define SZ(x) ((int)(x).size())
#define PB push_back
#define PF push_front
#define POB pop_back
#define POF pop_front
#define MP make_pair
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef map<int,int> mpi;
typedef set<int> sti;
typedef vector<pii> vii;
typedef map<pii,int> mpii;
typedef set<pii> stii;
typedef long double ld;
typedef long long ll;
int gcd(int x,int y){ return (!y ? x : gcd(y, x%y)); }
int power(int x, int y) { return (!y ? 1 : power(x, y / 2) * power(x, y / 2) * (y % 2 ? x : 1)); }
int to_int(string sconvert){stringstream geek(sconvert);int xconvert = 0; geek >> xconvert; return xconvert;}
int fastMax(int x, int y) { return (((y-x)>>(32-1))&(x^y))^y; }
int fastMin(int x, int y) { return (((y-x)>>(32-1))&(x^y))^x; }
const int MAXN=2e5+30,MAX_LOG=30,MOD=1e9+7,INF=1e17;
const double PI = acos(-1);
int mod(int x) { return (x % MOD + MOD) % MOD; }

int n, m, q;
vi g[600];
vi org_g[600];
int visited[600];
int cap[515][515];

int dfs(int v, int flow){
    if(v == n){
        return flow;}
    visited[v] = 1;
    for(int u : g[v]){
        if(!visited[u] && cap[v][u] > 0){
            int pushed = dfs(u, min(flow, cap[v][u]));
            if(pushed > 0){
                cap[v][u] -= pushed;
                cap[u][v] += pushed;
                return pushed;
            }
        }
    }
    return 0;
}

int find_route(int v, vi &route){
    route.PB(v);
    if(v == n){
        return 1;
    }
    visited[v] = 1;
    for(int u : org_g[v]){
        if(!visited[u] && cap[v][u] == 0){
            cap[v][u] = -1;
            if(find_route(u, route)){
                return 1;
            }
            cap[v][u] = 0;
        }
    }
    route.POB();
    return 0;
}
int MAIN(){
    cin>>n>>m;
    for (int i = 0; i < m; i++){
        int u,v;
        cin>>u>>v;
        g[u].push_back(v);
        g[v].PB(u);
        org_g[u].PB(v);
        cap[u][v]++;
    }

    int flow = 0;
    while(true){
        for (int i = 0; i < 600; i++){
            visited[i]=0;
        }
        
        int push = dfs(1, INF);
        if(push == 0){
            break;
        }
        flow+= push;
    }

    cout<<flow<<endl;
    for(int i=0;i<flow;i++){
        for (int i = 0; i < 600; i++){
            visited[i] = 0;
        }
        vi route;
        find_route(1, route);

        cout<<route.size()<<endl;
        for(int j=0; j< (int)route.size(); j++){
            cout<<route[j]<<' ';
        }
        cout<<endl;
    }
 

    return 0;
}

int32_t main(){
    IOS;
    int t=1;
    //cin>>t;
    while(t--)MAIN();
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED