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Submission #41707

# Submission time Handle Problem Language Result Execution time Memory
41707 2018-02-21T02:15:27 Z fallingstar Skyscraper (JOI16_skyscraper) C++14
100 / 100
 89 ms 16376 KB 
/**
    Problem: Skyscraper
    Source: JOI Open Contest 2016 Problem 3
    Solution: Connected Component DP
*/

#include <cstdio>
#include <algorithm>

using namespace std;

#define long long long

const int N = 100 + 2;
const int MOD = 1e9 + 7;
const int L = 1000 + 2;

void AddMod(int &a, int b) { a += b; if (a >= MOD) a -= MOD; }
int MulMod(int a, int b) { return (long) a * b % MOD; }

int n, lim, a[N], dp[N][N][L][3];

int main()
{
    scanf("%d %d", &n, &lim);
    for (int i = 1; i <= n; ++i) scanf("%d", &a[i]);
    sort(a + 1, a + 1 + n);

    dp[0][0][0][0] = 1;
    for (int i = 0; i < n; ++i)
        for (int j = 0; j <= i; ++j)
            for (int k = 0; k <= lim; ++k)
                for (int l = 0; l <= 2; ++l)
                {
                    int new_k = k + (a[i + 1] - a[i]) * (j * 2 - l);
                    if (new_k > lim || !dp[i][j][k][l]) continue;

                    // add new component
                    AddMod(dp[i + 1][j + 1][new_k][l], MulMod(dp[i][j][k][l], j - 1 + 2 - l));
                    if (l < 2) AddMod(dp[i + 1][j + 1][new_k][l + 1], MulMod(dp[i][j][k][l], 2 - l));

                    // connect two component
                    if (j >= 2) AddMod(dp[i + 1][j - 1][new_k][l], MulMod(dp[i][j][k][l], j - 1));

                    // to component's end
                    if (j > 0) AddMod(dp[i + 1][j][new_k][l], MulMod(dp[i][j][k][l], j * 2 - l));
                    if (j > 0 && l < 2) AddMod(dp[i + 1][j][new_k][l + 1], MulMod(dp[i][j][k][l], 2 - l));
                }

    int res = 0;
    for (int k = 0; k <= lim; ++k)
        AddMod(res, dp[n][1][k][2]);

    printf("%d", n > 1 ? res : 1);
    return 0;
}

Compilation message

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:25:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &lim);
                             ^
skyscraper.cpp:26:52: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for (int i = 1; i <= n; ++i) scanf("%d", &a[i]);
                                                    ^

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 1 ms 428 KB Output is correct
4 Correct 2 ms 536 KB Output is correct
5 Correct 2 ms 668 KB Output is correct
6 Correct 2 ms 852 KB Output is correct
7 Correct 1 ms 852 KB Output is correct
8 Correct 1 ms 852 KB Output is correct
9 Correct 2 ms 852 KB Output is correct
10 Correct 1 ms 852 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 940 KB Output is correct
2 Correct 2 ms 940 KB Output is correct
3 Correct 2 ms 944 KB Output is correct
4 Correct 2 ms 944 KB Output is correct
5 Correct 2 ms 944 KB Output is correct
6 Correct 2 ms 944 KB Output is correct
7 Correct 1 ms 944 KB Output is correct
8 Correct 2 ms 944 KB Output is correct
9 Correct 2 ms 944 KB Output is correct
10 Correct 2 ms 944 KB Output is correct

Subtask #3
80.0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 1 ms 428 KB Output is correct
4 Correct 2 ms 536 KB Output is correct
5 Correct 2 ms 668 KB Output is correct
6 Correct 2 ms 852 KB Output is correct
7 Correct 1 ms 852 KB Output is correct
8 Correct 1 ms 852 KB Output is correct
9 Correct 2 ms 852 KB Output is correct
10 Correct 1 ms 852 KB Output is correct
11 Correct 2 ms 940 KB Output is correct
12 Correct 2 ms 940 KB Output is correct
13 Correct 2 ms 944 KB Output is correct
14 Correct 2 ms 944 KB Output is correct
15 Correct 2 ms 944 KB Output is correct
16 Correct 2 ms 944 KB Output is correct
17 Correct 1 ms 944 KB Output is correct
18 Correct 2 ms 944 KB Output is correct
19 Correct 2 ms 944 KB Output is correct
20 Correct 2 ms 944 KB Output is correct
21 Correct 3 ms 1620 KB Output is correct
22 Correct 89 ms 16376 KB Output is correct
23 Correct 50 ms 16376 KB Output is correct
24 Correct 55 ms 16376 KB Output is correct
25 Correct 62 ms 16376 KB Output is correct
26 Correct 46 ms 16376 KB Output is correct
27 Correct 35 ms 16376 KB Output is correct
28 Correct 49 ms 16376 KB Output is correct
29 Correct 65 ms 16376 KB Output is correct
30 Correct 56 ms 16376 KB Output is correct