Submission #1114789

#	Time	Username	Problem	Language	Result	Execution time	Memory
1114789		FucKanh	Toll (BOI17_toll)	C++14	100 / 100	271 ms	34628 KiB

toll

#include<bits/stdc++.h>
#define ll long long
#define int ll
#define pii pair<int,int>
#define p3i pair<int,pii>

using namespace std;

const int inf = 1e15;
const int maxn = 5e4 + 2;
const int maxq = 1e4 + 2;

int k,n,m,q;
int ans[maxq];
int d[maxn][7][7];
vector<pii> a[maxn],b[maxn];

int cv(int tk, int lvl) {
    return (lvl-1) * k + tk;
}

pii cv(int u) {
    return make_pair(u % k, u / k + 1);
}

void query(int l, int r, vector<p3i> qr) {
    if (qr.size()==0) return;
    if (l==r) {
        for (p3i val : qr) {
            int id = val.first;
            ans[id] = (val.second.first == val.second.second) ? 0 : -1;
        }
        return;
    }

    for (int i = 1; i <= n; i++) {
        for (int u = 0; u < k; u++) {
            for (int v = 0; v < k; v++) {
                d[i][u][v] = inf;
            }
        }
    }

    int mid = l + r >> 1;
    for (int i = 0; i < k; i++) d[mid][i][i] = 0;

    for (int i = mid - 1; i >= l; i--) {
        for (int u = 0; u < k; u++) {
            int f = cv(u,i);
            for(pii val : a[f]) {
                int g,t; tie(g,t) =  val;
                int um = cv(g).first;
                for (int v = 0; v < k; v++) {
                    int h = cv(v,mid);
                    if (cv(v,mid) >= n) continue;
                    if (d[i+1][um][v] < inf) {
                        d[i][u][v] = min(d[i][u][v], d[i+1][um][v] + t);
                    }
                }
            }
        }
    }

    for (int i = mid + 1; i <= r; i++) {
        for (int u = 0; u < k; u++) {
            int f = cv(u,i);
            if (f >= n) continue;
            for(pii val : b[f]) {
                int g,t; tie(g,t) =  val;
                int um = cv(g).first;
                for (int v = 0; v < k; v++) {
                    int h = cv(v,mid);
                    if (d[i-1][v][um] < inf) {
                        d[i][v][u] = min(d[i][v][u], d[i-1][v][um] + t);
                    }
                }
            }
        }
    }
    vector<p3i> qrl,qrr;
    for (p3i val : qr) {
        int l,r; tie(l,r) = val.second;
        int u,lvlu; tie(u,lvlu) = cv(l);
        int v,lvlv; tie(v,lvlv) = cv(r);
        int id = val.first;
        if (lvlv <= mid) qrl.push_back(val);
        else if (lvlu >mid) qrr.push_back(val);
        else {
            ans[id] = inf;
            for (int f = 0; f < k; f++) {
                ans[id] = min(ans[id], d[lvlu][u][f] + d[lvlv][f][v]);
            }
            if (ans[id] >= inf) ans[id] = -1;
        }
    }

    query(l,mid,qrl);
    query(mid+1,r,qrr);
}

void solve() {
    cin >> k >> n >> m >> q;
    int lvl = n / k + (n%k != 0);
    for (int i = 1; i <= m; i++) {
        int x,y,t; cin >> x >> y >> t;
        a[x].push_back({y,t});
        b[y].push_back({x,t});
    }

    vector<p3i> qr;
    for (int i = 1; i <= q; i++){
        int x,y; cin >> x >> y;
        qr.push_back({i,{x,y}});
    }
    query(1,lvl,qr);
    for (int i = 1; i <= q; i++) {
        cout << ans[i] << '\n';
    }
}
void file(string name) {
    if (fopen((name + ".inp").c_str(), "r")) {
        freopen((name + ".inp").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    }
}
signed main() {
    file("toll");
    cin.tie(0) -> sync_with_stdio(0);
    solve();
    return 0;
}

Compilation message (stderr)

toll.cpp: In function 'void query(long long int, long long int, std::vector<std::pair<long long int, std::pair<long long int, long long int> > >)':
toll.cpp:44:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   44 |     int mid = l + r >> 1;
      |               ~~^~~
toll.cpp:54:25: warning: unused variable 'h' [-Wunused-variable]
   54 |                     int h = cv(v,mid);
      |                         ^
toll.cpp:72:25: warning: unused variable 'h' [-Wunused-variable]
   72 |                     int h = cv(v,mid);
      |                         ^
toll.cpp: In function 'void file(std::string)':
toll.cpp:122:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  122 |         freopen((name + ".inp").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
toll.cpp:123:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  123 |         freopen((name + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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