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Submission #110814

# Submission time Handle Problem Language Result Execution time Memory
110814 2019-05-12T09:30:54 Z tictaccat Boat (APIO16_boat) C++14
9 / 100
 5 ms 512 KB 
#include <bits/stdc++.h>

using namespace std;

#define int long long

const int MAX = 500 + 5;
const int MOD = 1e9 + 7;
const int INV2 = 5e8 + 4;

int N,ans;
vector<int> a(MAX), b(MAX), ways(2*MAX), newWays(2*MAX), bin; //ways[i] = ways of ending between bin[i] and bin[i+1]-1

main() {

    cin >> N;

    for (int i = 0; i < N; i++) {
        cin >> a[i] >> b[i];
        b[i]++;
        bin.push_back(a[i]);
        bin.push_back(b[i]);
    }

    sort(bin.begin(),bin.end());
    bin.erase(unique(bin.begin(),bin.end()),bin.end());

    for (int i = 0; i < N; i++) {
        int pre = 1, k = 0;
        for (; bin[k] < a[i]; k++) {pre += ways[k]; pre %= MOD;}
        for (; k+1 < bin.size() && bin[k+1] <= b[i]; k++) {
            int sz = bin[k+1] - bin[k];
            newWays[k] += pre + ways[k] * sz % MOD * (sz-1) % MOD * INV2 % MOD;
            newWays[k] %= MOD;
            pre += ways[k]*sz;
            pre %= MOD;
        }
        ways = newWays;
    }

    for (int k = 0; k < bin.size()-1; k++) {ans += ways[k]*(bin[k+1]-bin[k]); ans %= MOD;}

    cout << (ans < 0 ? ans + MOD : ans) << "\n";

    return 0;
}

Compilation message

boat.cpp:14:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() {
      ^
boat.cpp: In function 'int main()':
boat.cpp:31:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (; k+1 < bin.size() && bin[k+1] <= b[i]; k++) {
                ~~~~^~~~~~~~~~~~
boat.cpp:41:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int k = 0; k < bin.size()-1; k++) {ans += ways[k]*(bin[k+1]-bin[k]); ans %= MOD;}
                     ~~^~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 384 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 4 ms 512 KB Output is correct
6 Correct 4 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 4 ms 384 KB Output is correct
10 Correct 4 ms 384 KB Output is correct
11 Correct 3 ms 384 KB Output is correct
12 Correct 4 ms 384 KB Output is correct
13 Correct 4 ms 512 KB Output is correct
14 Correct 4 ms 384 KB Output is correct
15 Correct 4 ms 384 KB Output is correct
16 Correct 3 ms 384 KB Output is correct
17 Correct 2 ms 384 KB Output is correct
18 Correct 3 ms 384 KB Output is correct
19 Correct 3 ms 384 KB Output is correct
20 Correct 3 ms 384 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 384 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 4 ms 512 KB Output is correct
6 Correct 4 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 4 ms 384 KB Output is correct
10 Correct 4 ms 384 KB Output is correct
11 Correct 3 ms 384 KB Output is correct
12 Correct 4 ms 384 KB Output is correct
13 Correct 4 ms 512 KB Output is correct
14 Correct 4 ms 384 KB Output is correct
15 Correct 4 ms 384 KB Output is correct
16 Correct 3 ms 384 KB Output is correct
17 Correct 2 ms 384 KB Output is correct
18 Correct 3 ms 384 KB Output is correct
19 Correct 3 ms 384 KB Output is correct
20 Correct 3 ms 384 KB Output is correct
21 Incorrect 4 ms 384 KB Output isn't correct
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 384 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 384 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 4 ms 512 KB Output is correct
6 Correct 4 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 4 ms 384 KB Output is correct
10 Correct 4 ms 384 KB Output is correct
11 Correct 3 ms 384 KB Output is correct
12 Correct 4 ms 384 KB Output is correct
13 Correct 4 ms 512 KB Output is correct
14 Correct 4 ms 384 KB Output is correct
15 Correct 4 ms 384 KB Output is correct
16 Correct 3 ms 384 KB Output is correct
17 Correct 2 ms 384 KB Output is correct
18 Correct 3 ms 384 KB Output is correct
19 Correct 3 ms 384 KB Output is correct
20 Correct 3 ms 384 KB Output is correct
21 Incorrect 4 ms 384 KB Output isn't correct
22 Halted 0 ms 0 KB -