oj.uz

Submission #52967

# Submission time Handle Problem Language Result Execution time Memory
52967 2018-06-27T11:31:18 Z evpipis Boat (APIO16_boat) C++11
27 / 100
 2000 ms 17888 KB 
#include <bits/stdc++.h>
using namespace std;

#define pb push_back
const int len = 105, mod = 1e9+7;
int n, m = 0;
int po[2*len], dp[len][2*len][len][2], bi[2*len][len], l[len], r[len];
vector<int> vec;

int add(int a, int b){
    return (a+b)%mod;
}

int mul(int a, int b){
    return (a*1LL*b)%mod;
}

int pw(int a, int b){
    if (b == 0) return 1;
    if (b%2 == 0) return pw(mul(a, a), b/2);
    return mul(a, pw(mul(a, a), b/2));
}

int solve(int i, int j, int k, int t){
    if (i == 0 || j == 0) return (k == 0);
    if (dp[i][j][k][t] != -1) return dp[i][j][k][t];

    int ans = 0;
    if (k == 0){
        for (int x = 0; x <= i; x++){
            ans = add(ans, mul(solve(i, j-1, x, 0), bi[j-1][x]));
            ans = add(ans, mul(solve(i, j-1, x, 1), bi[j-1][x-1]));
        }
    }
    else{
        ans = add(ans, solve(i-1, j, k, t));
        if (t == 0 && l[i] <= po[j-1]+1 && po[j]-1 <= r[i])
            ans = add(ans, solve(i-1, j, k-1, 0));
        if (t == 1 && l[i] <= po[j] && po[j] <= r[i])
            ans = add(ans, solve(i-1, j, k-1, 0));
    }

    //printf("(%d, %d, %d, %d) = %d\n", i, j, k, t, ans);
    return dp[i][j][k][t] = ans;
}

int main(){
    scanf("%d", &n);
    for (int i = 1; i <= n; i++){
        scanf("%d %d", &l[i], &r[i]);
        vec.pb(l[i]), vec.pb(r[i]);
    }

    sort(vec.begin(), vec.end());
    for (int i = 0; i < vec.size(); i++)
        if (vec[i] != po[m])
            po[++m] = vec[i];

    //for (int i = 0; i <= m; i++)
      //  printf("i = %d, poi = %d\n", i, po[i]);

    for (int i = 0; i <= m; i++){
        bi[i][0] = 1;
        int s = po[i]-po[i-1] - 1;
        for (int k = 1; k <= min(s, n); k++)
            bi[i][k] = mul(bi[i][k-1], mul(s-k+1, pw(k, mod-2)));
    }

    for (int i = 0; i <= n; i++)
        for (int j = 0; j <= m+1; j++)
            for (int k = 0; k <= i; k++)
                dp[i][j][k][0] = dp[i][j][k][1] = -1;

    printf("%d\n", add(solve(n, m+1, 0, 0), mod-1));
    return 0;
}

Compilation message

boat.cpp: In function 'int main()':
boat.cpp:55:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < vec.size(); i++)
                     ~~^~~~~~~~~~~~
boat.cpp:48:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
boat.cpp:50:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &l[i], &r[i]);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Execution timed out 2073 ms 7960 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Execution timed out 2073 ms 7960 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 100 ms 17592 KB Output is correct
2 Correct 86 ms 17712 KB Output is correct
3 Correct 86 ms 17712 KB Output is correct
4 Correct 87 ms 17864 KB Output is correct
5 Correct 88 ms 17864 KB Output is correct
6 Correct 103 ms 17864 KB Output is correct
7 Correct 115 ms 17864 KB Output is correct
8 Correct 94 ms 17884 KB Output is correct
9 Correct 97 ms 17884 KB Output is correct
10 Correct 102 ms 17888 KB Output is correct
11 Correct 110 ms 17888 KB Output is correct
12 Correct 91 ms 17888 KB Output is correct
13 Correct 91 ms 17888 KB Output is correct
14 Correct 95 ms 17888 KB Output is correct
15 Correct 124 ms 17888 KB Output is correct
16 Correct 44 ms 17888 KB Output is correct
17 Correct 42 ms 17888 KB Output is correct
18 Correct 40 ms 17888 KB Output is correct
19 Correct 47 ms 17888 KB Output is correct
20 Correct 45 ms 17888 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Execution timed out 2073 ms 7960 KB Time limit exceeded
2 Halted 0 ms 0 KB -