oj.uz

Submission #40163

# Submission time Handle Problem Language Result Execution time Memory
40163 2018-01-28T19:56:09 Z evpipis Skyscraper (JOI16_skyscraper) C++
100 / 100
 126 ms 131868 KB 
#include <bits/stdc++.h>
using namespace std;

const int len = 105, mod = 1e9+7;
int n, a[len], dp[len][len][1005][3];

int solve(int i, int j, int rem, int l){
    if (j < 0 || rem < 0 || l > 2) return 0;
    //printf("cur_state = %d, %d, %d, %d\n", i, j, rem, l);
    if (i == n+1) return (j == 1 && l == 2);
    if (dp[i][j][rem][l] != -1) return dp[i][j][rem][l];

    int ans = 0, c = a[i+1]-a[i];
    // Case 1: combine 2 ccs
    if (j >= 2){
        int temp = solve(i+1, j-1, rem-c*(2*(j-1)-l), l);
        if (l == 0)
            ans = (ans + j*(j-1)*1LL*temp)%mod;
        else if (l == 1)
            ans = (ans + (j-1)*(j-1)*1LL*temp)%mod;
        else{
            if (i == n) ans = (ans+temp)%mod;
            else ans = (ans + (j-2)*(j-1)*1LL*temp)%mod;
        }
    }

    // Case 2: create +1 cc
    // do not add an endpoint
    ans = (ans+solve(i+1, j+1, rem-c*(2*(j+1)-l), l))%mod;
    // add an  endpoint
    ans = (ans+(2-l)*1LL*solve(i+1, j+1, rem-c*(2*(j+1)-l-1), l+1))%mod;
    //i think its right!

    // just enlarge 1 cc
    if (j){
        // do not add an endpoint
        ans = (ans+(2*j-l)*1LL*solve(i+1, j, rem-c*(2*j-l), l))%mod;
        // add an endpoint
        int temp = solve(i+1, j, rem-c*(2*j-l-1), l+1);
        if (i == n)
            ans = (ans+(2-l)*j*1LL*temp)%mod;
        else
            ans = (ans+(2-l)*(j-l)*1LL*temp)%mod;
    }
    //if this is right...something else is wrong...

    return dp[i][j][rem][l] = ans;
}

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

    if (n == 1){
        printf("1\n");
        return 0;
    }

    for (int i = 1; i <= n; i++)
        for (int j = 0; j <= n; j++)
            for (int rem = 0; rem <= l; rem++)
                dp[i][j][rem][0] = dp[i][j][rem][1] = dp[i][j][rem][2] = -1;

    printf("%d\n", solve(1, 0, l, 0));
    return 0;
}

Compilation message

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:52:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &l);
                           ^
skyscraper.cpp:54:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &a[i]);
                           ^

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 131868 KB Output is correct
2 Correct 0 ms 131868 KB Output is correct
3 Correct 0 ms 131868 KB Output is correct
4 Correct 0 ms 131868 KB Output is correct
5 Correct 1 ms 131868 KB Output is correct
6 Correct 0 ms 131868 KB Output is correct
7 Correct 0 ms 131868 KB Output is correct
8 Correct 1 ms 131868 KB Output is correct
9 Correct 1 ms 131868 KB Output is correct
10 Correct 0 ms 131868 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 131868 KB Output is correct
2 Correct 1 ms 131868 KB Output is correct
3 Correct 1 ms 131868 KB Output is correct
4 Correct 1 ms 131868 KB Output is correct
5 Correct 1 ms 131868 KB Output is correct
6 Correct 0 ms 131868 KB Output is correct
7 Correct 0 ms 131868 KB Output is correct
8 Correct 1 ms 131868 KB Output is correct
9 Correct 1 ms 131868 KB Output is correct
10 Correct 1 ms 131868 KB Output is correct

Subtask #3
80.0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 131868 KB Output is correct
2 Correct 0 ms 131868 KB Output is correct
3 Correct 0 ms 131868 KB Output is correct
4 Correct 0 ms 131868 KB Output is correct
5 Correct 1 ms 131868 KB Output is correct
6 Correct 0 ms 131868 KB Output is correct
7 Correct 0 ms 131868 KB Output is correct
8 Correct 1 ms 131868 KB Output is correct
9 Correct 1 ms 131868 KB Output is correct
10 Correct 0 ms 131868 KB Output is correct
11 Correct 1 ms 131868 KB Output is correct
12 Correct 1 ms 131868 KB Output is correct
13 Correct 1 ms 131868 KB Output is correct
14 Correct 1 ms 131868 KB Output is correct
15 Correct 1 ms 131868 KB Output is correct
16 Correct 0 ms 131868 KB Output is correct
17 Correct 0 ms 131868 KB Output is correct
18 Correct 1 ms 131868 KB Output is correct
19 Correct 1 ms 131868 KB Output is correct
20 Correct 1 ms 131868 KB Output is correct
21 Correct 0 ms 131868 KB Output is correct
22 Correct 126 ms 131868 KB Output is correct
23 Correct 63 ms 131868 KB Output is correct
24 Correct 107 ms 131868 KB Output is correct
25 Correct 88 ms 131868 KB Output is correct
26 Correct 84 ms 131868 KB Output is correct
27 Correct 34 ms 131868 KB Output is correct
28 Correct 52 ms 131868 KB Output is correct
29 Correct 96 ms 131868 KB Output is correct
30 Correct 90 ms 131868 KB Output is correct