Submission #727219

#	Time	Username	Problem	Language	Result	Execution time	Memory
727219		josanneo22	Travelling Merchant (APIO17_merchant)	C++17	100 / 100	54 ms	1364 KiB

merchant

#pragma GCC optimize(Ofast)
#pragma GCC optimization (unroll-loops)
#pragma GCC optimize(3)
#include<bits/stdc++.h>
using namespace std;
using ll=long long;
 
const int maxn = int(1e2) + 11;
const int maxk = int(1e3) + 11;
const ll inf = 0x3f3f3f3f * ((1ll<<32)+1);
 
int n, m, knd;
int buy[maxn][maxk], sell[maxn][maxk];
ll de[maxn][maxn];
int mxsell[maxn][maxn];
 
#define Floyd(d) { \
	for (int j=1; j<=n; ++j) { \
		for (int i=1; i<=n; ++i) for (int k=1; k<=n; ++k) \
			d[i][k] = min(d[i][k], d[i][j] + d[j][k]); \
	} \
}
 
inline int rd(){
	int x=0,w=1;
	char ch=getchar();
	for(;ch>'9'||ch<'0';ch=getchar()) if(ch=='-') w=-1;
	for(;ch>='0'&&ch<='9';ch=getchar()) x=(x<<1) +(x<<3) +ch-'0';
	return x*w;
}
int main() {
	cin.tie(0)->sync_with_stdio(0); cout.tie(0);
	n=rd(),m=rd(),knd=rd();
	for (int i=1; i<=n; ++i) for (int j=1; j<=knd; ++j) {
		buy[i][j]=rd();sell[i][j]=rd();
	}
	memset(de, 0x3f, sizeof(de));
	for (int i=1; i<=m; ++i) {
		int f=rd(), t=rd(), v=rd();
		de[f][t] = min(de[f][t], ll(v));
	}
	Floyd(de);
	
	for (int t=1; t<=knd; ++t) {
		for (int i=1; i<=n; ++i) if (buy[i][t] != -1)
		for (int j=1; j<=n; ++j) if (sell[j][t] != -1) {
			mxsell[i][j] = max(mxsell[i][j], sell[j][t]-buy[i][t]);
		}
	}
	//compare profit/time>=some value
	//profit>=some value *time
	//profit-some_value*time>=0
	int ql=-1, qr=int(1e9)+10;
	while (ql+1 < qr) {
		int c = (ql+qr)>>1;
		static ll dc[maxn][maxn];
		for (int i=1; i<=n; ++i) for (int j=1; j<=n; ++j) {
			if (de[i][j] == inf) dc[i][j] = inf;
			else dc[i][j] = c*1ll*de[i][j]-mxsell[i][j];
		}
		Floyd(dc);
		bool loop = false;
		for (int i=1; i<=n; ++i) if (dc[i][i] <= 0) { loop = true; break; }
		//if i to go i is negative,meaning there is a negative loop
		(loop ? ql : qr) = c;
	}
	printf("%d",ql);
 
	return 0;
}

Compilation message (stderr)

merchant.cpp:3: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    3 | #pragma GCC optimization (unroll-loops)
      | 
merchant.cpp:2:22: warning: '#pragma GCC optimize' is not a string or number [-Wpragmas]
    2 | #pragma GCC optimize(Ofast)
      |                      ^~~~~

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