Submission #563897

#	Time	Username	Problem	Language	Result	Execution time	Memory
563897		maomao90	Wild Boar (JOI18_wild_boar)	C++17	0 / 100	1 ms	980 KiB

wild_boar

// Hallelujah, praise the one who set me free
// Hallelujah, death has lost its grip on me
// You have broken every chain, There's salvation in your name
// Jesus Christ, my living hope
#include <bits/stdc++.h> 
using namespace std;

template <class T>
inline bool mnto(T& a, T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}
#define REP(i, s, e) for (int i = s; i < e; i++)
#define RREP(i, s, e) for (int i = s; i >= e; i--)
typedef long long ll;
typedef long double ld;
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
typedef vector<iii> viii;

#ifndef DEBUG
#define cerr if (0) cerr
#endif

const int INF = 1000000005;
const ll LINF = 1000000000000000005ll;
const int MAXN = 6005;
const int MAXL = 100005;

int n, m, t, l, e;
vi adj[MAXN], radj[MAXN];
int w[MAXN];
int x[MAXL];
ll rd[MAXN][MAXN][4];
ll dp[MAXL][2];

ll dist[MAXN][MAXN];
int fi[MAXN][MAXN], se[MAXN][MAXN];
priority_queue<pll, vector<pll>, greater<pll>> pq;
void dijkstra(int s) {
    REP (i, 0, e) {
        dist[s][i] = LINF;
        fi[s][i] = se[s][i] = -1;
    }
    dist[s][s] = w[s];
    pq.push(pll{w[s], s});
    while (!pq.empty()) {
        auto [d, u] = pq.top(); pq.pop();
        if (d != dist[s][u]) continue;
        for (int v : adj[u]) {
            ll nd = d + w[v];
            if (mnto(dist[s][v], nd)) {
                pq.push(pll{nd, v});
                fi[s][v] = fi[s][u] == -1 ? v : fi[s][u];
                se[s][v] = u;
            }
        }
    }
}

int main() {
#ifndef DEBUG
    ios::sync_with_stdio(0), cin.tie(0);
#endif
    cin >> n >> m >> t >> l;
    e = n + 1;
    if (e & 1) {
        e++;
    }
    REP (i, 0, m) {
        int a, b, c; cin >> a >> b >> c;
        w[e] = c;
        adj[a].pb(e);
        adj[e].pb(b);
        radj[a].pb(e++);
        w[e] = c;
        adj[b].pb(e);
        adj[e].pb(a);
        radj[b].pb(e++);
    }
    REP (i, 1, e) {
        dijkstra(i);
    }
    REP (i, 1, n + 1) {
        REP (j, i + 1, n + 1) {
            REP (z, 0, 4) {
                rd[i][j][z] = LINF;
            }
            //rd[i][j][3] = dist[i][j];
            for (int u : radj[i]) {
                for (int v : radj[j]) {
                    v ^= 1;
                    int tp = 0;
                    auto onPath = [&] (int x) {
                        return dist[u][v] == dist[u][x] + dist[x][v] - w[x];
                    };
                    if (onPath(fi[i][j])) {
                        tp |= 1;
                    }
                    if (onPath(se[i][j])) {
                        tp |= 2;
                    }
                    mnto(rd[i][j][tp], dist[u][v]);
                }
            }
            assert(rd[i][j][3] == dist[i][j]);
            REP (z, 0, 4) {
                rd[j][i][z] = rd[i][j][z];
                cerr << i << ' ' << j << ' ' << z << ": " << rd[i][j][z] << '\n';
            }
            cerr << ' ' << fi[i][j] << ' ' << se[i][j] << '\n';
        }
    }
    x[0] = -1;
    REP (i, 1, l + 1) {
        cin >> x[i];
    }
    while (t--) {
        int p, q; cin >> p >> q;
        x[p] = q;
        dp[1][0] = dp[1][1] = 0;
        REP (i, 2, l + 1) {
            int p = x[i - 2], u = x[i - 1], v = x[i];
            int f = fi[u][v], s = p == -1 ? -1 : se[p][u];
            REP (j, 0, 2) {
                dp[i][j] = LINF;
                REP (k, 0, 2) {
                    REP (l, 0, 2) {
                        if (k == 1 && l == 1 && f ^ 1 == s) continue;
                        mnto(dp[i][j], dp[i - 1][k] + rd[u][v][(l << 1) + j]);
                    }
                }
                cerr << i << ' ' << j << ": " << dp[i][j] << '\n';
            }
        }
        ll ans = min(dp[l][0], dp[l][1]);
        if (ans >= LINF) {
            ans = -1;
        }
        cout << ans << '\n';
    }
    return 0;
}

Compilation message (stderr)

wild_boar.cpp: In function 'int main()':
wild_boar.cpp:137:55: warning: suggest parentheses around comparison in operand of '^' [-Wparentheses]
  137 |                         if (k == 1 && l == 1 && f ^ 1 == s) continue;
      |                                                     ~~^~~~

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