Submission #370056

#	Time	Username	Problem	Language	Result	Execution time	Memory
370056		79brue	Travelling Merchant (APIO17_merchant)	C++14	100 / 100	120 ms	4204 KiB

merchant

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

int n, m, k;
vector<pair<int, ll> > link[102];
ll buy[102][1002], sell[102][1002];

ll dist[102][102];
ll profit[102][102];
ll tDist[102][102];

bool able(ll key){
    for(int i=1; i<=n; i++){
        for(int j=1; j<=n; j++){
            tDist[i][j] = profit[i][j] - key * dist[i][j];
        }
    }

    for(int d=1; d<=n; d++){
        for(int i=1; i<=n; i++){
            for(int j=1; j<=n; j++){
                tDist[i][j] = max(tDist[i][j], tDist[i][d] + tDist[d][j]);
            }
        }
    }

    for(int i=1; i<=n; i++){
        if(tDist[i][i] >= 0) return true;
    }
    return false;
}

int main(){
    scanf("%d %d %d", &n, &m, &k);
    for(int i=1; i<=n; i++){
        for(int j=1; j<=k; j++){
            scanf("%lld %lld", &buy[i][j], &sell[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++){
        int x, y; ll z;
        scanf("%d %d %lld", &x, &y, &z);
        dist[x][y] = z;
    }

    for(int d=1; d<=n; d++){
        for(int i=1; i<=n; i++){
            for(int j=1; j<=n; j++){
                dist[i][j] = min(dist[i][j], dist[i][d] + dist[d][j]);
            }
        }
    }

    for(int i=1; i<=n; i++){
        for(int j=1; j<=n; j++){
            for(int x=1; x<=k; x++){
                if(min({sell[j][x], buy[i][x]}) == -1) continue;
                profit[i][j] = max(profit[i][j], sell[j][x] - buy[i][x]);
            }
        }
    }

    ll MIN = 0, MAX = 1e9, ANS = 0;
    while(MIN <= MAX){
        ll MID = (MIN + MAX) / 2;
        if(able(MID)){
            ANS = MID;
            MIN = MID+1;
        }
        else MAX = MID-1;
    }
    printf("%lld", ANS);
}

Compilation message (stderr)

merchant.cpp: In function 'int main()':
merchant.cpp:37:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   37 |     scanf("%d %d %d", &n, &m, &k);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:40:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   40 |             scanf("%lld %lld", &buy[i][j], &sell[i][j]);
      |             ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
merchant.cpp:47:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   47 |         scanf("%d %d %lld", &x, &y, &z);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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