Submission #1266598

#	Time	Username	Problem	Language	Result	Execution time	Memory
1266598		ilovewaguri	Drivers (BOI24_drivers)	C++20	0 / 100	3 ms	4932 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define NAME "DRIVERS"
#define nl '\n'
#define allofa(x,sz) x,x+sz+1
#define allof(x) x.begin(),x.end()
#define allof1(x) x.begin()+1,x.end()
#define mset(x,val) memset(x,val,sizeof(x))
#define couf(x) cout << fixed << setprecision(x)
template<class T> T Abs(T &x) {return (x>=0 ? x : -x);};
template<class X,class Y> bool minimize(X &a, Y b){if(a>b) {a=b;return true;}return false;};
template<class X,class Y> bool maximize(X &a, Y b){if(a<b) {a=b;return true;}return false;};
typedef long long ll;
typedef pair<ll,int> pli;
const ll mod = (long long)1e9+7;
const ll LINF = (long long)1e15;
const int INF = (int)1e9;
const int MAXN = (int)2e5+5;
vector<pli> graph[MAXN];
set<int> isSub1;
int n,m,q;

void ccps() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    if(fopen(NAME".inp","r")) {
        freopen(NAME".inp","r",stdin);
        freopen(NAME".out","w",stdout);
    }
}

namespace subtask1 {
    const int N = (int)1e4+5;
    ll dist[N][N];

    bool check() {
        return (int)isSub1.size()==1 and 1<=n and n<=1e4 and 1<=m and m<=1e4;
    }

    void bfs(int src) {
        fill(allofa(dist[src],n+1),INF);
        queue<int> q;
        q.push(src);
        dist[src][src]=0;
        while(!q.empty()) {
            int u = q.front();q.pop();
            for (pli x : graph[u]) {
                int v = x.second;
                if(dist[src][v]==INF) {
                    dist[src][v]=dist[src][u]+1;
                    q.push(v);
                }
            }
        }
    }

    void sol() {
        int w = *isSub1.begin();
        for (int u = 1; u<=n; u++) bfs(u);
        for (int u = 1; u<=n; u++) {
            for (int v = 1; v<=n; v++) {
                if(dist[u][v]==INF) continue;
                else dist[u][v]*=w;
            }
        }
        while(q--) {
            int x,y,t; cin >> x >> y >> t;
            if(dist[x][y]>t) cout << "NO" << nl;
            else cout << "YES" << nl;
        }
    }
}

signed main() {
    ccps();
    cin >> n >> m >> q;
    for (int i = 1; i<=m; i++) {
        int u,v; ll w; cin >> u >> v >> w;
        graph[u].push_back({w,v});
        graph[v].push_back({w,u});
        isSub1.insert(w);
    }
    if(subtask1::check()) subtask1::sol();
    else cout << "NO";
}

Compilation message (stderr)

Main.cpp: In function 'void ccps()':
Main.cpp:27:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |         freopen(NAME".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
Main.cpp:28:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |         freopen(NAME".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 11
• Subtask 3: 0 / 11
• Subtask 4: 0 / 23
• Subtask 5: 0 / 45