Submission #416840

#	Time	Username	Problem	Language	Result	Execution time	Memory
416840		Mamnoon_Siam	Wild Boar (JOI18_wild_boar)	C++17	12 / 100	1 ms	332 KiB

wild_boar

#include <bits/stdc++.h>
using namespace std;

using ii = pair<int, int>;
using ll = long long;
using vi = vector<int>;
#define fi first
#define se second
#define all(v) begin(v), end(v)
#define sz(v) (int)(v.size())
using pli = pair<ll, int>;

const int N = 50;
const ll inf = 1e18;

int n, m, T, L;
int A[N], B[N], C[N];
vi ine[N], oute[N];
ll cost[N][N]; // cost[i][j] = shortest path from i-th directed edge to j-th directed edge
ll dp[N][N];
int X[N];

ll f(int i, int prv) {
  ll& ret = dp[i][prv];
  if(~ret) return ret;
  if(i == L) return ret = 0;
  int a = X[i], b = X[i+1];
  ret = inf;
  for(int u : oute[a]) if((u>>1) != prv) {
    for(int v : ine[b]) {
      ret = min(ret, f(i+1, v>>1) + cost[u][v]);
    }
  }
  return ret;
}

#ifdef LOCAL
#include "../debug.h"
#else
#define debug(...)
#endif
int main(int argc, char const *argv[])
{
#ifdef LOCAL
  freopen("in", "r", stdin);
#endif
  scanf("%d %d %d %d", &n, &m, &T, &L);
  for(int i = 1; i <= m; ++i) {
    scanf("%d %d %d", &A[2*i], &B[2*i], &C[2*i]);
    A[2*i+1] = B[2*i];
    B[2*i+1] = A[2*i];
    C[2*i+1] = C[2*i];
    ine[B[2*i]].emplace_back(2*i);
    oute[A[2*i]].emplace_back(2*i);
    ine[B[2*i+1]].emplace_back(2*i+1);
    oute[A[2*i+1]].emplace_back(2*i+1);
  }
  for(int i = 1; i <= n; ++i) {
    debug(ine[i], oute[i]);
  }
  for(int i = 1; i <= L; ++i) {
    scanf("%d", &X[i]);
  }
  for(int src = 2; src <= 2*m+1; ++src) {
  // for(int src : {4}) {
    vector<bool> done(2*m+2);
    ll *dis = cost[src];
    fill(dis+2, dis+2*m+2, inf);
    debug(vector<ll>(dis+2, dis+2*m+2));
    dis[src] = C[src];
    debug(dis[src]);
    priority_queue<pli, vector<pli>, less<pli>> Q;
    Q.emplace(dis[src], src);
    while(sz(Q)) {
      int u = Q.top().se;
      debug(u);
      Q.pop();
      // if(done[u]) continue;
      done[u] = 1;
      for(int v : oute[B[u]]) if((u^v)>>1) {
        debug(v);
        ll nw = dis[u] + C[v];
        debug(nw);
        debug(dis[7]);
        if(nw < dis[v]) {
          dis[v] = nw;
          Q.emplace(dis[v], v);
        }
      }
    }
    debug(dis[7]);
  }
  // debug(cost[4][7]);
  // debug(cost[2][8]);
  /*for(int i : oute[4]) {
    for(int j : ine[1]) {
      debug(i, j, cost[i][j]);
    }
  }
  for(int i : oute[1]) {
    for(int j : ine[4]) {
      debug(i, j, cost[i][j]);
    }
  }*/
  while(T--) {
    int p, q;
    scanf("%d %d", &p, &q);
    X[p] = q;

    debug(vi(X+1, X+1+L));

    memset(dp, -1, sizeof dp);
    printf("%lld\n", f(1, 0) == inf ? -1 : f(1, 0));
  }
  return 0;
}

Compilation message (stderr)

wild_boar.cpp: In function 'int main(int, const char**)':
wild_boar.cpp:47:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |   scanf("%d %d %d %d", &n, &m, &T, &L);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
wild_boar.cpp:49:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |     scanf("%d %d %d", &A[2*i], &B[2*i], &C[2*i]);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
wild_boar.cpp:62:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |     scanf("%d", &X[i]);
      |     ~~~~~^~~~~~~~~~~~~
wild_boar.cpp:107:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  107 |     scanf("%d %d", &p, &q);
      |     ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 0 / 35
• Subtask 3: 0 / 15
• Subtask 4: 0 / 38