oj.uz

Submission #22991

# Submission time Handle Problem Language Result Execution time Memory
22991 2017-05-01T03:01:32 Z model_code Hacker (BOI15_hac) C++11
100 / 100
 706 ms 25164 KB 
/*
    Task: Hacker
    Model Solution 1
    Author: Krzysztof Kiljan
    Complexity: O(n log n)
    Uses set to calculate maximum on all ranges
 */

#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <set>

using namespace std;

#define REP(I,N) for(int I=0;I<(N);I++)
#define PB push_back
#define MP make_pair
#define ST first
#define ND second


typedef vector<int> VI;
typedef pair<int, int> PII;
typedef long long ll;

const int MAXN = 500013;
VI v;

int n, m, k, operCompNum, myCompNum;

// sums[i] = v[i] + ... v[i +myCompNum -1]
VI sums;

//Holds pairs <value, index in sums array>
set <PII> curSums;

void readInput()
{
    scanf("%d", &n);

    operCompNum = n / 2;
    myCompNum = n - operCompNum;

    REP(i, n)
    {
        scanf("%d", &k);
        v.PB(k);
    }
}

//makes   v -> vvv, for easier further implementation

void duplicateV()
{
    REP(j, 2)
    REP(i, n)
    v.push_back(v[i]);
}

// Precomputes sum of values of computers in range <start, start + myCompNum)
// for all starts possible
void precompSums()
{
    int sum = 0;
    int curStart = 0;
    int end = curStart + myCompNum;

    for (int i = curStart; i < end; i++)
        sum += v[i];

    sums.PB(sum);

    while (curStart < 2 * n)
    {
        sum -= v[curStart];
        curStart++;
        sum += v[end];
        end++;
        sums.PB(sum);
    }
}

PII calcMaxAns()
{
    int curStart = n - myCompNum + 1;
    int end = curStart + myCompNum;
    PII ans = MP(-1, -1);

    for (int i = curStart; i < end; i++)
        curSums.insert(MP(sums[i], i));

    ans = *(curSums.begin());

    while (end < 2 * n)
    {
        curSums.erase(MP(sums[curStart], curStart));
        curStart++;
        curSums.insert(MP(sums[end], end));
        end++;

        if (ans.ST < (*(curSums.begin())).ST)
        {
            ans = *(curSums.begin());
        }
    }

    return ans;
}

int solve()
{
    precompSums();
    PII ans = calcMaxAns();

    return ans.ST;
}

int main()
{
    readInput();
    duplicateV();
    int ans = solve();
    printf("%d\n", ans);
    return 0;
}

Compilation message

hac.cpp: In function 'void readInput()':
hac.cpp:41:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
                    ^
hac.cpp:48:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &k);
                        ^

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 1176 KB Output is correct
2 Correct 0 ms 1176 KB Output is correct
3 Correct 0 ms 1176 KB Output is correct
4 Correct 0 ms 1176 KB Output is correct
5 Correct 0 ms 1176 KB Output is correct
6 Correct 0 ms 1176 KB Output is correct
7 Correct 0 ms 1176 KB Output is correct
8 Correct 0 ms 1176 KB Output is correct
9 Correct 0 ms 1176 KB Output is correct
10 Correct 0 ms 1176 KB Output is correct
11 Correct 0 ms 1176 KB Output is correct
12 Correct 0 ms 1176 KB Output is correct
13 Correct 0 ms 1176 KB Output is correct
14 Correct 0 ms 1176 KB Output is correct
15 Correct 0 ms 1176 KB Output is correct
16 Correct 0 ms 1176 KB Output is correct
17 Correct 0 ms 1176 KB Output is correct
18 Correct 0 ms 1176 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 1176 KB Output is correct
2 Correct 0 ms 1176 KB Output is correct
3 Correct 0 ms 1176 KB Output is correct
4 Correct 0 ms 1176 KB Output is correct
5 Correct 0 ms 1176 KB Output is correct
6 Correct 0 ms 1176 KB Output is correct
7 Correct 0 ms 1176 KB Output is correct
8 Correct 0 ms 1176 KB Output is correct
9 Correct 0 ms 1176 KB Output is correct
10 Correct 0 ms 1176 KB Output is correct
11 Correct 0 ms 1176 KB Output is correct
12 Correct 0 ms 1176 KB Output is correct
13 Correct 0 ms 1176 KB Output is correct
14 Correct 0 ms 1176 KB Output is correct
15 Correct 0 ms 1176 KB Output is correct
16 Correct 0 ms 1176 KB Output is correct
17 Correct 0 ms 1176 KB Output is correct
18 Correct 0 ms 1176 KB Output is correct
19 Correct 0 ms 1176 KB Output is correct
20 Correct 0 ms 1176 KB Output is correct
21 Correct 0 ms 1176 KB Output is correct
22 Correct 0 ms 1316 KB Output is correct
23 Correct 3 ms 1448 KB Output is correct
24 Correct 0 ms 1316 KB Output is correct
25 Correct 0 ms 1448 KB Output is correct
26 Correct 3 ms 1448 KB Output is correct
27 Correct 0 ms 1176 KB Output is correct
28 Correct 0 ms 1176 KB Output is correct
29 Correct 0 ms 1176 KB Output is correct
30 Correct 0 ms 1448 KB Output is correct
31 Correct 0 ms 1448 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 1176 KB Output is correct
2 Correct 0 ms 1176 KB Output is correct
3 Correct 3 ms 1448 KB Output is correct
4 Correct 56 ms 5156 KB Output is correct
5 Correct 206 ms 12088 KB Output is correct
6 Correct 266 ms 13144 KB Output is correct
7 Correct 286 ms 16448 KB Output is correct
8 Correct 706 ms 25164 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 1176 KB Output is correct
2 Correct 0 ms 1176 KB Output is correct
3 Correct 0 ms 1176 KB Output is correct
4 Correct 0 ms 1176 KB Output is correct
5 Correct 0 ms 1176 KB Output is correct
6 Correct 0 ms 1176 KB Output is correct
7 Correct 0 ms 1176 KB Output is correct
8 Correct 0 ms 1176 KB Output is correct
9 Correct 0 ms 1176 KB Output is correct
10 Correct 0 ms 1176 KB Output is correct
11 Correct 0 ms 1176 KB Output is correct
12 Correct 0 ms 1176 KB Output is correct
13 Correct 0 ms 1176 KB Output is correct
14 Correct 0 ms 1176 KB Output is correct
15 Correct 0 ms 1176 KB Output is correct
16 Correct 0 ms 1176 KB Output is correct
17 Correct 0 ms 1176 KB Output is correct
18 Correct 0 ms 1176 KB Output is correct
19 Correct 0 ms 1176 KB Output is correct
20 Correct 0 ms 1176 KB Output is correct
21 Correct 0 ms 1176 KB Output is correct
22 Correct 0 ms 1316 KB Output is correct
23 Correct 3 ms 1448 KB Output is correct
24 Correct 0 ms 1316 KB Output is correct
25 Correct 0 ms 1448 KB Output is correct
26 Correct 3 ms 1448 KB Output is correct
27 Correct 0 ms 1176 KB Output is correct
28 Correct 0 ms 1176 KB Output is correct
29 Correct 0 ms 1176 KB Output is correct
30 Correct 0 ms 1448 KB Output is correct
31 Correct 0 ms 1448 KB Output is correct
32 Correct 0 ms 1176 KB Output is correct
33 Correct 0 ms 1176 KB Output is correct
34 Correct 3 ms 1448 KB Output is correct
35 Correct 56 ms 5156 KB Output is correct
36 Correct 206 ms 12088 KB Output is correct
37 Correct 266 ms 13144 KB Output is correct
38 Correct 286 ms 16448 KB Output is correct
39 Correct 706 ms 25164 KB Output is correct
40 Correct 3 ms 1648 KB Output is correct
41 Correct 9 ms 2168 KB Output is correct
42 Correct 16 ms 2676 KB Output is correct
43 Correct 189 ms 12088 KB Output is correct
44 Correct 603 ms 25164 KB Output is correct
45 Correct 73 ms 6672 KB Output is correct
46 Correct 269 ms 16448 KB Output is correct
47 Correct 686 ms 25164 KB Output is correct
48 Correct 333 ms 25164 KB Output is correct
49 Correct 336 ms 25164 KB Output is correct
50 Correct 329 ms 25164 KB Output is correct