Submission #838484

#	Time	Username	Problem	Language	Result	Execution time	Memory
838484		nonono	Travelling Merchant (APIO17_merchant)	C++14	100 / 100	59 ms	5400 KiB

merchant

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

const int INF = 1e18;
const int mxN = 1005;

int N, M, K;
int b[mxN][mxN], s[mxN][mxN];
int d[mxN][mxN], dd[mxN][mxN], f[mxN][mxN];

bool find_path(int x) {
    for(int i = 1; i <= N; i ++) {
        for(int j = 1; j <= N; j ++) {
            f[i][j] = dd[i][j] - d[i][j] * x;
        }
    }
    
    for(int k = 1; k <= N; k ++) {
        for(int i = 1; i <= N; i ++) {
            for(int j = 1; j <= N; j ++) {
                f[i][j] = max(f[i][j], f[i][k] + f[k][j]);
            }
        }
    }
    
    int max_Dist = - INF;
    for(int i = 1; i <= N; i ++) max_Dist = max(max_Dist, f[i][i]);
    return max_Dist >= 0;
}

signed main() {
#define taskname ""

    if(fopen(taskname".inp", "r")) {
        freopen(taskname".inp", "r", stdin);
        freopen(taskname".out", "w", stdout);
    }

    cin.tie(0)->sync_with_stdio(0);
    
    cin >> N >> M >> K;
    
    for(int i = 1; i <= N; i ++) {
        for(int j = 1; j <= K; j ++) {
            cin >> b[i][j] >> s[i][j];
        }
    }
    
    for(int i = 1; i <= N; i ++) {
        for(int j = 1; j <= N; j ++) {
            d[i][j] = (long long) 1E9;
        }
    }
    
    for(int i = 1; i <= M; i ++) {
        int u, v, w;
        cin >> u >> v >> w;
        d[u][v] = min(d[u][v], w);
    }
    
    for(int k = 1; k <= N; k ++) {
        for(int i = 1; i <= N; i ++) {
            for(int j = 1; j <= N; j ++) {
                d[i][j] = min(d[i][j], d[i][k] + d[k][j]);
            }
        }
    }
    
    for(int i = 1; i <= K; i ++) {
        for(int j = 1; j <= N; j ++) {
            if(b[j][i] == -1) continue ;
            
            for(int k = 1; k <= N; k ++) {
                if(s[k][i] == -1) continue ;
                dd[j][k] = max(dd[j][k], s[k][i] - b[j][i]);
            }
        }
    }
    
    int low = 1, high = (long long) 1E9;
    while(low <= high) {
        int mid = (low + high) / 2;
        if(find_path(mid) == true) low = mid + 1; else high = mid - 1;
    }
    
    cout << low - 1 << "\n";
    return 0;
}

Compilation message (stderr)

merchant.cpp: In function 'int main()':
merchant.cpp:36:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         freopen(taskname".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:37:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |         freopen(taskname".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 21 / 21
• Subtask 3: 33 / 33
• Subtask 4: 34 / 34