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Submission #639364

# Submission time Handle Problem Language Result Execution time Memory
639364 2022-09-09T16:28:35 Z PoonYaPat Boat (APIO16_boat) C++14
0 / 100
 224 ms 4376 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

const ll mod=1e9+7;
ll n,c[1001],st[501],ed[501],cnt,comb[501];
ll dp[501][1001];
set<int> ss;

ll power(int a, int m) { //a^m;
    ll ans=1;
    while (m) {
        if (m%2==1) ans=(ans*a)%mod;
        a=(a*a)%mod;
        m/=2;
    }
    return ans;
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin>>n;
    for (int i=1; i<=n; ++i) {
        cin>>st[i]>>ed[i]; --st[i];
        ss.insert(st[i]);
        ss.insert(ed[i]);
    }

    for (int i=1; i<=n; ++i) comb[i]=power(i,mod-2)%mod;

    cnt=ss.size()-1;
    int id=0;
    for (auto it=ss.begin(); it!=ss.end(); ++it) c[id++]=*it;

    for (int i=0; i<=cnt; ++i) dp[0][i]=1;

    for (int i=1; i<=n; ++i) {
        dp[i][0]=1; //don't send any boat

        for (int j=1; j<=cnt; ++j) { //consider from the range from c[j-1]+1 to c[j]
            dp[i][j]=dp[i][j-1];

            ll idx=1,com=1;
            for (auto k=i; k>0; --k) {
                if (st[k]<c[j] && c[j]<=ed[k]) {
                    com=((com*(c[j]-c[j-1]+idx-1)%mod)*comb[idx])%mod;
                    dp[i][j]=(dp[i][j]+dp[k-1][j-1]*com)%mod;
                    ++idx;
                }
            }
        }
    }
    cout<<(dp[n][cnt]-1+mod)%mod;
}

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 224 ms 4240 KB Output is correct
2 Correct 221 ms 4180 KB Output is correct
3 Correct 217 ms 4176 KB Output is correct
4 Correct 215 ms 4264 KB Output is correct
5 Correct 217 ms 4376 KB Output is correct
6 Correct 132 ms 4300 KB Output is correct
7 Correct 132 ms 4244 KB Output is correct
8 Correct 139 ms 4204 KB Output is correct
9 Correct 138 ms 4356 KB Output is correct
10 Correct 131 ms 4280 KB Output is correct
11 Correct 131 ms 4208 KB Output is correct
12 Correct 138 ms 4296 KB Output is correct
13 Correct 132 ms 4172 KB Output is correct
14 Correct 124 ms 4232 KB Output is correct
15 Correct 134 ms 4208 KB Output is correct
16 Incorrect 47 ms 3020 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 224 ms 4240 KB Output is correct
2 Correct 221 ms 4180 KB Output is correct
3 Correct 217 ms 4176 KB Output is correct
4 Correct 215 ms 4264 KB Output is correct
5 Correct 217 ms 4376 KB Output is correct
6 Correct 132 ms 4300 KB Output is correct
7 Correct 132 ms 4244 KB Output is correct
8 Correct 139 ms 4204 KB Output is correct
9 Correct 138 ms 4356 KB Output is correct
10 Correct 131 ms 4280 KB Output is correct
11 Correct 131 ms 4208 KB Output is correct
12 Correct 138 ms 4296 KB Output is correct
13 Correct 132 ms 4172 KB Output is correct
14 Correct 124 ms 4232 KB Output is correct
15 Correct 134 ms 4208 KB Output is correct
16 Incorrect 47 ms 3020 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 5 ms 852 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 224 ms 4240 KB Output is correct
2 Correct 221 ms 4180 KB Output is correct
3 Correct 217 ms 4176 KB Output is correct
4 Correct 215 ms 4264 KB Output is correct
5 Correct 217 ms 4376 KB Output is correct
6 Correct 132 ms 4300 KB Output is correct
7 Correct 132 ms 4244 KB Output is correct
8 Correct 139 ms 4204 KB Output is correct
9 Correct 138 ms 4356 KB Output is correct
10 Correct 131 ms 4280 KB Output is correct
11 Correct 131 ms 4208 KB Output is correct
12 Correct 138 ms 4296 KB Output is correct
13 Correct 132 ms 4172 KB Output is correct
14 Correct 124 ms 4232 KB Output is correct
15 Correct 134 ms 4208 KB Output is correct
16 Incorrect 47 ms 3020 KB Output isn't correct
17 Halted 0 ms 0 KB -