Submission #295280

#	Time	Username	Problem	Language	Result	Execution time	Memory
295280		BeanZ	Travelling Merchant (APIO17_merchant)	C++14	100 / 100	86 ms	4424 KiB

merchant

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define endl '\n'
const int N = 1e5 + 5;
ll dp[105][105], p[105][105], dist[105][105], b[105][1005], s[105][1005];
bool chk(ll mid, ll n){
        memset(dp, 0, sizeof(dp));
        for (int i = 1; i <= n; i++){
                for (int j = 1; j <= n; j++){
                        dp[i][j] = p[i][j] - mid * dist[i][j];
                }
        }
        for (int k = 1; k <= n; k++){
                for (int i = 1; i <= n; i++){
                        for (int j = 1; j <= n; j++){
                                if (i != j) dp[i][j] = max(dp[i][j], dp[i][k] + dp[k][j]);
                        }
                }
        }
        for (int i = 1; i <= n; i++){
                for (int j = i + 1; j <= n; j++){
                        if ((dp[i][j] + dp[j][i]) >= 0) return true;
                }
        }
        return false;
}
int main(){
        ios_base::sync_with_stdio(false);
        cin.tie(0);
        if (fopen("balance.in", "r")){
                freopen("balance.in", "r", stdin);
                freopen("balance.out", "w", stdout);
        }
        ll n, m, k;
        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++){
                        dist[i][j] = 1e9;
                }
        }
        for (int i = 1; i <= m; i++){
                ll u, v, c;
                cin >> u >> v >> c;
                dist[u][v] = c;
        }
        for (int x = 1; x <= n; x++){
                for (int i = 1; i <= n; i++){
                        for (int j = 1; j <= n; j++){
                                dist[i][j] = min(dist[i][j], dist[i][x] + dist[x][j]);
                        }
                }
        }
        for (int x = 1; x <= k; x++){
                for (int i = 1; i <= n; i++){
                        for (int j = 1; j <= n; j++){
                                if (b[i][x] > 0 && s[j][x] > 0) p[i][j] = max(p[i][j], s[j][x] - b[i][x]);
                        }
                }
        }
        ll l = 0, h = 1e9;
        while (l <= h){
                ll mid = (l + h) >> 1;
                if (chk(mid, n)) l = mid + 1;
                else h = mid - 1;
        }
        cout << max(h, 0ll);
}
/*
*/

Compilation message (stderr)

merchant.cpp: In function 'int main()':
merchant.cpp:34:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   34 |                 freopen("balance.in", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:35:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   35 |                 freopen("balance.out", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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