CSES - HIIT Open 2018 - Results
Submission details
Task:Buy Low, Sell High
Sender:Puhi~
Submission time:2018-05-26 13:33:58
Language:C++
Status:READY
Result:
Test results
testverdicttime
#1ACCEPTED0.10 sdetails
#2ACCEPTED0.19 sdetails
#3ACCEPTED0.18 sdetails
#40.24 sdetails
#5ACCEPTED0.24 sdetails
#6ACCEPTED0.01 sdetails
#7ACCEPTED0.01 sdetails
#8ACCEPTED0.01 sdetails
#9ACCEPTED0.09 sdetails

Code

#include <iostream>
#include <stdint.h>

using namespace std;

int64_t prices[500000];

int main() {
    int n;
    cin >> n;

    for (int i = 0; i < n; i++) {
        cin >> prices[i];
    }
    
    int start = 0;
    int64_t best = 0;
    int best_pos = 0;

    for (int i = 0; i < n; i++) {
        if (prices[i] < prices[start]) {
            start = i;
        }
        
        int64_t p = prices[i] - prices[start];
        if (p > best) {
            best = p;
            best_pos = i;
        }
    }
    
    int bstart = start;
    int bend = best_pos;
    int64_t bbest = best;
    
    //
    start = 0;
    best = 0;
    best_pos = 0;
    
    for (int i = 0; i <= bstart; i++) {
        if (prices[i] < prices[start]) {
            start = i;
        }
        
        int64_t p = prices[i] - prices[start];
        if (p > best) {
            best = p;
            best_pos = i;
        }
    }
    
    int64_t abest = best;
    
    //
    start = bend;
    best = 0;
    best_pos = bend;

    for (int i = bend; i < n; i++) {
        if (prices[i] < prices[start]) {
            start = i;
        }
        
        int64_t p = prices[i] - prices[start];
        if (p > best) {
            best = p;
            best_pos = i;
        }
    }
    
    int64_t ebest = best;
    
    //
    start = bend;
    best = 0;
    best_pos = bend;

    for (int i = bend; i > bstart; i--) {
        if (prices[i] < prices[start]) {
            start = i;
        }
        
        int64_t p = prices[i] - prices[start];
        if (p > best) {
            best = p;
            best_pos = i;
        }
    }
    
    int64_t drop = best;
    
    cout << max(bbest + abest, max(bbest + ebest, bbest + drop)) << endl;
    
}

Test details

Test 1

Verdict: ACCEPTED

input
500000
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ...

correct output
0

user output
0

Test 2

Verdict: ACCEPTED

input
500000
1 2 3 4 5 6 7 8 9 10 11 12 13 ...

correct output
499999

user output
499999

Test 3

Verdict: ACCEPTED

input
500000
500000 499999 499998 499997 49...

correct output
0

user output
0

Test 4

Verdict:

input
500000
617752857 533265574 365848360 ...

correct output
1999980408

user output
1999989982

Test 5

Verdict: ACCEPTED

input
500000
209620375 316066031 756114325 ...

correct output
1999992655

user output
1999992655

Test 6

Verdict: ACCEPTED

input
1
1

correct output
0

user output
0

Test 7

Verdict: ACCEPTED

input
2
1 1

correct output
0

user output
0

Test 8

Verdict: ACCEPTED

input
2
2 1

correct output
0

user output
0

Test 9

Verdict: ACCEPTED

input
500000
1 1000000000 2 2 2 2 2 2 2 2 2...

correct output
1999999998

user output
1999999998