Distinct Routes

input/code.cpp: In function 'll bfs(int, int, std::vector<int>&)':
input/code.cpp:99:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   99 |     for (int i = 0; i < p.size(); i++) p[i]=-1;
      |                     ~~^~~~~~~~~~
input/code.cpp: In function 'int solve()':
input/code.cpp:134:18: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  134 |     while(nw_flow=bfs(0, n-1, p)) {
      |           ~~~~~~~^~~~~~~~~~~~~~~
input/code.cpp:152:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  152 |     for (int i = 0; i < res.size(); i++) {
      |                     ~~^~~~~~~~~~~~
input/code.cpp:154:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsig...

#ifdef ONPC
    #define _GLIBCXX_DEBUG
#endif
#include <bits/stdc++.h>

#define char unsigned char
#define rep(i, a, b) for(int i=a; i< (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
#define eb emplace_back
#define mp make_pair
#define mt make_tuple
#define fi first
#define se second
#define pb push_back

#define LSOne(S) ((S) & -(S))

using namespace std;
// mt19937 rnd(239);
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

template <typename T> int sgn(T x) { return (T(0) < x) - (x < T(0)); }
typedef long double T;
typedef complex<T> pt;
#define X real()
#define Y imag()

template<class T>
istream& operator>> (istream& is, complex<T>& p) {
    T value;
    is >> value;
    p.real(value);
    is >> value;
    p.imag(value);
    return is;
}

typedef long long ll;
typedef long double ld;

using pi = pair<ll, ll>;
using vi = vector<ll>;
template <class T>
using pq = priority_queue<T>;
template <class T>
using pqg = priority_queue<T, vector<T>, greater<T>>;

int popcnt(int x) { return __builtin_popcount(x); }
int popcnt(ll x) { return __builtin_popcountll(x); }

#define MIN(v) *min_element(all(v))
#define MAX(v) *max_element(all(v))
#define LB(c, x) distance((c).begin(), lower_bound(all(c), (x)))
#define UB(c, x) distance((c).begin(), upper_bound(all(c), (x)))

void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef DEBUG
#define dbg(x...) cerr << "\e[91m"<<__func__<<":"<<__LINE__<<" [" << #x << "] = ["; _print(x); cerr << "\e[39m" << endl;
#else
#define dbg(x...)
#endif

template<typename S, typename T = S> void chmin(S &s, T t) {s = s < t ? s : t;}
template<typename S, typename T = S> void chmax(S &s, T t) {s = s > t ? s : t;}

const int INF = 1e9; // 10^9 = 1B is < 2^31-1
const ll LLINF = 4e18; // 4*10^18 is < 2^63-1
const double EPS = 1e-9;
const ll MOD = 1e9+7;

const int N=1010;
ll cap[N][N];
vector<int> adj[N];
 
int n, m;
 
ll bfs(int s, int t, vector<int> &p) {
    for (int i = 0; i < p.size(); i++) p[i]=-1;
    p[s]=-2;
    queue<pair<int,ll>> q;
    q.push({s, LLINF});
    
    while(!q.empty()) {
        ll curr=q.front().fi;
        ll flow=q.front().se;
        q.pop();
        
        for(auto &w:adj[curr]) {
            if(p[w]==-1 && cap[curr][w]) {
                p[w]=curr;
                ll nw_flow=min(flow, cap[curr][w]);
                if(w==t) return nw_flow;
                q.push({w, nw_flow});
            }
        }
    }
 
    return 0;
}

int solve() {
    int n, m; std::cin >> n >> m;
    for (int i = 0; i < m; i++) {
        int a,b; std::cin >> a >> b;
        a--; b--;
        adj[a].pb(b);
        cap[a][b]+=1;
    }

    vector<vector<int>> res;
    vector<int> p(n);    
    ll flow=0, nw_flow;
    while(nw_flow=bfs(0, n-1, p)) {
        flow+=nw_flow;
        int curr=n-1;
        vector<int> newPath={curr};
        while(curr!=0) {
            int prev=p[curr];
            cap[prev][curr]-=nw_flow;
            cap[curr][prev]+=nw_flow;
            curr=prev;
            newPath.pb(curr);
        }
        reverse(all(newPath));
        for (int j = 0; j < nw_flow; j++) {    
            res.pb(newPath);
        }
    }
 
    std::cout << flow << std::endl;
    for (int i = 0; i < res.size(); i++) {
        std::cout << res[i].size() << std::endl;
        for (int j = 0; j < res[i].size(); j++) {
            std::cout << res[i][j]+1 << " ";
        }
        std::cout  << std::endl;
    }
 

    return 0;
}

int32_t main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    int TET = 1;
    //cin >> TET;
    for (int i = 1; i <= TET; i++) {
        #ifdef ONPC
            cout << "TEST CASE#" << i << endl;
        #endif
        
        if (solve()) {
            break;
        }

        #ifdef ONPC
            cout << "__________________________" << endl;
        #endif
    }
    #ifdef ONPC
        cerr << endl << "finished in " << clock() * 1.0 / CLOCKS_PER_SEC << " sec" << endl;
    #endif
}

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: WRONG ANSWER

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: WRONG ANSWER