Submission #200315

#	Time	Username	Problem	Language	Result	Execution time	Memory
200315		BThero	Travelling Merchant (APIO17_merchant)	C++17	0 / 100	1099 ms	1912 KiB

merchant

// Why am I so dumb? :c
// chrono::system_clock::now().time_since_epoch().count()
                                                  
#include<bits/stdc++.h>
//#include<ext/pb_ds/assoc_container.hpp>
//#include<ext/pb_ds/tree_policy.hpp>

#define pb push_back
#define mp make_pair

#define all(x) (x).begin(), (x).end()

#define fi first
#define se second

using namespace std;
//using namespace __gnu_pbds;

typedef long long ll;   
typedef pair<int, int> pii;
//template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const int MAXN = (int)1e2 + 5;
const int MAXK = (int)1e3 + 5;
const ll LINF = (ll)1e17;

int buy[MAXN][MAXK], sell[MAXN][MAXK];

ll dp[MAXN][MAXK];

int adj[MAXN][MAXN];

int n, m, k;

bool check(int x) {
    for (int st = 1; st <= n; ++st) {
        for (int i = 1; i <= n; ++i) {
            for (int j = 0; j <= k; ++j) {
                dp[i][j] = -LINF;
            }
        }

        for (int to = 1; to <= n; ++to) {
            if (adj[st][to] == -1) {
                continue;
            }
            
            ll w = adj[st][to] * 1ll * x;
            dp[to][0] = -w;

            for (int i = 1; i <= k; ++i) {
                if (buy[st][i] != -1) {
                    dp[to][i] = -w - buy[st][i];
                }
            }                                                            
        }

        bool changed = 1;
        int iter = 0;

        while (changed && iter <= n) {
            changed = 0;
            ++iter;

            if (dp[st][0] >= 0) {
                return 1;
            }

            for (int v = 1; v <= n; ++v) {
                for (int i = 1; i <= k; ++i) {
                    if (dp[v][i] == -LINF || sell[v][i] == -1) {
                        continue;
                    }                    

                    if (dp[v][i] + sell[v][i] > dp[v][0]) {
                        dp[v][0] = dp[v][i] + sell[v][i];
                        changed = 1;
                    }
                }

                if (dp[v][0] != -LINF) {
                    for (int i = 1; i <= k; ++i) {
                        if (buy[v][i] != -1) {
                            if (dp[v][0] - buy[v][i] > dp[v][i]) {
                                dp[v][i] = dp[v][0] - buy[v][i];
                                changed = 1;
                            }
                        } 
                    }
                }

                for (int i = 0; i <= k; ++i) {
                    if (dp[v][i] == -LINF) {
                        continue;
                    }

                    for (int to = 1; to <= n; ++to) {
                        if (adj[v][to] == -1) {
                            continue;
                        }

                        ll w = adj[v][to] * 1ll * x;

                        if (dp[v][i] - w > dp[to][i]) {
                            dp[to][i] = dp[v][i] - w;
                            changed = 1;
                        }
                    }
                }
            }
        }
    }

    return 0; 
}

void solve() {
    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]);
        }
    }

    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= n; ++j) {
            adj[i][j] = -1;
        }
    }

    for (int i = 1; i <= m; ++i) {
        int u, v, w;
        scanf("%d %d %d", &u, &v, &w);
        adj[u][v] = w;
    }

    int l = 1, r = (int)1e9, ans = 0;

    while (l <= r) {
        int mid = (l + r) >> 1;

        if (check(mid)) {
            l = mid + 1;
            ans = mid;
        }
        else {
            r = mid - 1;
        }
    }

    printf("%d\n", ans);
}

int main() {
    int tt = 1;

    while (tt--) {
        solve();
    }

    return 0;
}

Compilation message (stderr)

merchant.cpp: In function 'void solve()':
merchant.cpp:118:10: 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:122:18: 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:134:14: 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: 0 / 12
• Subtask 2: 0 / 21
• Subtask 3: 0 / 33
• Subtask 4: 0 / 34