Submission #1263590

#	Time	Username	Problem	Language	Result	Execution time	Memory
1263590		shiori_chan	Toll (BOI17_toll)	C++17	100 / 100	101 ms	63668 KiB

toll

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ii pair<int, int>
const int N = 1e6 + 5;
int upf[N][18][5];
int d[N];
vector<ii> a[N];
bool vis[N];
int k, n, m, o;
void bfs() {
    for (int u = n; u >= 0; u--) {
        for (auto P : a[u]) {
            upf[u][0][P.first % k] = min(upf[u][0][P.first % k], P.second);
        }
        for (int g = 1; g < 16; g++) {
            for (int j = 0; j < k; j++) {
                for (int p = 0; p < k; p++) {
                    int nodep = (u / k + (1 << (g-1))) * k + p;
                    upf[u][g][j] = min(upf[u][g][j], upf[u][g-1][p] + upf[nodep][g-1][j]);
                } 
            }
        }
    }
}
inline int jump(pair<int, int> x, pair<int, int> y) {
    int z = y.first - x.first;
    
    int currb[5] = {(int)1e16, (int)1e16, (int)1e16, (int)1e16, (int)1e16};
    currb[x.second] = 0;
    int floor = x.first;
    for (int j = 0; (1 << j) <= z; j++) {
        if ((z >> j) & 1) {
            int curr[5] = {(int)1e16, (int)1e16, (int)1e16, (int)1e16, (int)1e16};
            for (int p = 0; p < k; p++) {
                for (int y = 0; y < k; y++) {
                    curr[p] = min(curr[p], currb[y] + upf[floor*k+y][j][p]);
                }
            }
            floor += (1 << j);
            swap(curr, currb);
        }
    }
    return currb[y.second];
}
int query(int u, int v) {
    int x = jump({u / k, u % k}, {v / k, v % k});
    return x;
}  
signed main() {
    if (fopen("D.inp", "r")) {
        freopen("D.inp", "r", stdin);
        freopen("D.out", "w", stdout);
    }
    cin.tie(0)->sync_with_stdio(false);
    cin >> k >> n >> m >> o;
    for (int i = 0; i <= n; i++) {
        for (int j = 0; j < 20; j++) {
            for (int x = 0; x < k; x++) {
                upf[i][j][x] = 1e16;
                // up[i][j][x] = -1;
            }
        }
    }
    for (int i = 1; i <= m; i++){ 
        int u, v, w;
        cin >> u >> v >> w;
        a[u].push_back({v, w});
    }
    bfs();
    while (o--) {
        int u, v;
        cin >> u >> v;
        if (u / k > v/k || (u / k == v / k && u != v)) {
            cout << "-1\n";
            continue;
        }
        int x = query(u, v);
        if (x >= 1e16) cout << "-1\n";
        else cout << x << '\n';
    }
    return 0;
}

Compilation message (stderr)

toll.cpp: In function 'int main()':
toll.cpp:52:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |         freopen("D.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
toll.cpp:53:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   53 |         freopen("D.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 31 / 31
• Subtask 5: 44 / 44