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Submission #251137

# Submission time Handle Problem Language Result Execution time Memory
251137 2020-07-20T12:00:27 Z Sorting Calvinball championship (CEOI15_teams) C++14
100 / 100
 556 ms 780 KB 
#include <bits/stdc++.h>

using namespace std;

const int k_N = 1e4 + 3;
const long long k_Mod = 1e6 + 7;

int n, a[k_N];
long long dp[2][k_N][2];

long long solve(int pos, int cnt, bool equal){
    if(pos == n) return 1;
    return dp[pos & 1][cnt][equal];
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> n;
    for(int i = 0; i < n; ++i)
        cin >> a[i];

    for(int pos = n - 1; pos >= 0; --pos){
        for(int cnt = 0; cnt <= pos; ++cnt){
            for(short equal = 0; equal <= 1; ++equal){
                auto &ans = dp[pos & 1][cnt][equal];
                ans = 0;

                if(!equal){ 
                    ans = (solve(pos + 1, cnt, false) * cnt + solve(pos + 1, cnt + 1, false)) % k_Mod;
                    continue;
                }

                ans = solve(pos + 1, cnt, false) * min(cnt, a[pos] - 1) % k_Mod;
                if(a[pos] <= cnt)          ans += solve(pos + 1, cnt, true);
                else if(a[pos] == cnt + 1) ans += solve(pos + 1, cnt + 1, true);
                else if(a[pos] > cnt + 1)  ans += solve(pos + 1, cnt + 1, false);
                ans %= k_Mod;
            }
        }
    }

    cout << solve(0, 0, true) << "\n";
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 1 ms 512 KB Output is correct
3 Correct 0 ms 384 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 2 ms 384 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 384 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 5 ms 384 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 448 ms 740 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 109 ms 512 KB Output is correct
2 Correct 111 ms 512 KB Output is correct
3 Correct 119 ms 600 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 439 ms 760 KB Output is correct
2 Correct 427 ms 768 KB Output is correct
3 Correct 556 ms 780 KB Output is correct