Submission #1117459

#	Time	Username	Problem	Language	Result	Execution time	Memory
1117459		thtsshz_bgwrswh	Travelling Merchant (APIO17_merchant)	C++17	100 / 100	54 ms	4188 KiB

merchant

#include <stdio.h>
#include <algorithm>
using namespace std;
const long long INF = 1e18;
long long buy[105][1005], sell[105][1005];
long long graph[105][105], profit[105][105];
long long graph2[105][105];
long long n, m, x;

void floyd(long long graph[105][105]) {
    for (long long k = 1; k <= n; k++)
        for (long long i = 1; i <= n; i++)
            for (long long j = 1; j <= n; j++)
                graph[i][j] = min(graph[i][j], graph[i][k] + graph[k][j]);
}

int main() {
    scanf("%lld %lld %lld", &n, &m, &x);
    for (long long i = 1; i <= n; i++) {
        for (long long j = 1; j <= n; j++) graph[i][j] = INF;
        for (long long j = 1; j <= x; j++) {
            scanf("%lld %lld", &buy[i][j], &sell[i][j]);
        }
    }
    for (long long i = 0; i < m; i++) {
        long long u, v, c;
        scanf("%lld %lld %lld", &u, &v, &c);
        graph[u][v] = c;
    }
    floyd(graph);
    for (long long i = 1; i <= n; i++) {
        for (long long j = 1; j <= n; j++) {
            for (long long l = 1; l <= x; l++) {
                if (sell[j][l] != -1 && buy[i][l] != -1)
                    profit[i][j] = max(profit[i][j], sell[j][l] - buy[i][l]);
            }
        }
    }
    long long left = 1, right = 1e9;
    while (left <= right) {
        long long mid = (left + right) / 2;
        for (long long i = 1; i <= n; i++)
            for (long long j = 1; j <= n; j++)
                graph2[i][j] = mid * min(graph[i][j], INF / mid) - profit[i][j];
        floyd(graph2);
        bool has_nonnegative_cycle = false;
        for (long long i = 1; i <= n; i++)
            if (graph2[i][i] <= 0) has_nonnegative_cycle = true;
        if (has_nonnegative_cycle)
            left = mid + 1;
        else
            right = mid - 1;
    }
    printf("%lld\n", right);
}

Compilation message (stderr)

merchant.cpp: In function 'int main()':
merchant.cpp:18:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |     scanf("%lld %lld %lld", &n, &m, &x);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:22:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 |             scanf("%lld %lld", &buy[i][j], &sell[i][j]);
      |             ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:27:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |         scanf("%lld %lld %lld", &u, &v, &c);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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