Submission #52355

#	Time	Username	Problem	Language	Result	Execution time	Memory
52355		imeimi2000	Travelling Merchant (APIO17_merchant)	C++17	100 / 100	107 ms	9544 KiB

merchant

#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <unordered_map>
#include <functional>
#include <cstring>
#include <cmath>
#include <ctime>
#include <cstdlib>

using namespace std;
typedef long long llong;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<llong, llong> pll;

int n, k;
const int inf = 1e9 + 7;
const llong linf = (llong)inf * inf;
int buy[101][1001], sell[101][1001];
int t[101][101];
int c[101][101];
llong d[101][101];

int main() {
    int m;
    scanf("%d%d%d", &n, &m, &k);
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= k; ++j) {
            scanf("%d%d", buy[i] + j, sell[i] + j);
            if (buy[i][j] != -1 && buy[i][j] < sell[i][j]) exit(1);
        }
    }
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= n; ++j) {
            t[i][j] = inf;
        }
    }
    for (int i = 0; i < m; ++i) {
        int v, w, p;
        scanf("%d%d%d", &v, &w, &p);
        t[v][w] = p;
    }
    for (int p = 1; p <= n; ++p) {
        for (int i = 1; i <= n; ++i) {
            for (int j = 1; j <= n; ++j) {
                t[i][j] = min(t[i][j], t[i][p] + t[p][j]);
            }
        }
    }
    for (int i = 1; i <= k; ++i) {
        for (int j = 1; j <= n; ++j) {
            for (int p = 1; p <= n; ++p) {
                if (buy[j][i] != -1 && sell[p][i] != -1) {
                    c[j][p] = max(c[j][p], sell[p][i] - buy[j][i]);
                }
            }
        }
    }
    
    int s = 0, e = inf;
    while (s < e) {
        m = (s + e + 1) / 2;
        for (int i = 1; i <= n; ++i) {
            for (int j = 1; j <= n; ++j) {
                if (t[i][j] == inf) d[i][j] = linf;
                else d[i][j] = (llong)m * t[i][j] - c[i][j];
            }
        }
        for (int p = 1; p <= n; ++p) {
            for (int i = 1; i <= n; ++i) {
                for (int j = 1; j <= n; ++j) {
                    d[i][j] = min(d[i][j], d[i][p] + d[p][j]);
                }
            }
        }
        int ch = 0;
        for (int i = 1; i <= n; ++i) {
            if (d[i][i] <= 0) {
                ch = 1;
                break;
            }
        }
        if (ch) s = m;
        else e = m - 1;
    }
    printf("%d\n", s);
	return 0;
}

Compilation message (stderr)

merchant.cpp: In function 'int main()':
merchant.cpp:31:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d", &n, &m, &k);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:34:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d%d", buy[i] + j, sell[i] + j);
             ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:45:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d%d", &v, &w, &p);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~

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