Submission #77955

#	Time	Username	Problem	Language	Result	Execution time	Memory
77955		aquablitz11	Travelling Merchant (APIO17_merchant)	C++14	100 / 100	122 ms	9500 KiB

merchant

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

using ll = long long;

const int N = 110;
const int T = 1010;
const ll INF = 1e18;

int n, m, t;
int B[N][T], S[N][T];
ll pro[N][N], dist[N][N], A[N][N];

bool check(ll r)
{
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= n; ++j)
            A[i][j] = pro[i][j]-dist[i][j]*r;
        A[i][i] = -INF;
    }
    for (int k = 1; k <= n; ++k) {
        for (int i = 1; i <= n; ++i) {
            for (int j = 1; j <= n; ++j)
                A[i][j] = max(A[i][j], A[i][k]+A[k][j]);
        }
    }
    /*printf("check(%lld):\n", r);
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= n; ++j)
            printf("%lld ", A[i][j]);
        printf("\n");
    }
    printf("\n");*/
    for (int i = 1; i <= n; ++i) {
        if (A[i][i] >= 0)
            return true;
    }
    return false;
}

int main()
{
    scanf("%d%d%d", &n, &m, &t);
    for (int i = 1; i <= n; ++i) {
        dist[i][i] = 0;
        for (int j = 1; j <= t; ++j)
            scanf("%d%d", &B[i][j], &S[i][j]);
    }
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= n; ++j) {
            dist[i][j] = 1e9;
            for (int k = 1; k <= t; ++k) {
                if (B[i][k] != -1 && S[j][k] != -1)
                    pro[i][j] = max(pro[i][j], (ll)S[j][k]-B[i][k]);
            }
        }
        dist[i][i] = 0;
    }
    for (int i = 1; i <= m; ++i) {
        int u, v, w;
        scanf("%d%d%d", &u, &v, &w);
        dist[u][v] = w;
    }
    for (int k = 1; k <= n; ++k) {
        for (int i = 1; i <= n; ++i) {
            for (int j = 1; j <= n; ++j)
                dist[i][j] = min(dist[i][j], dist[i][k]+dist[k][j]);
        }
    }

    ll b = 0, e = 1e9;
    while (b < e) {
        ll m = (b+e+1)/2;
        if (check(m))
            b = m;
        else 
            e = m-1;
    }
    printf("%lld\n", b);

    return 0;
}

Compilation message (stderr)

merchant.cpp: In function 'int main()':
merchant.cpp:43:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d", &n, &m, &t);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:47:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d%d", &B[i][j], &S[i][j]);
             ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:61:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d%d", &u, &v, &w);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~

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