oj.uz

Submission #200738

# Submission time Handle Problem Language Result Execution time Memory
200738 2020-02-08T05:11:46 Z BThero Boat (APIO16_boat) C++17
27 / 100
 39 ms 17036 KB 
// Why am I so dumb? :c
// chrono::system_clock::now().time_since_epoch().count()
                                                  
#include<bits/stdc++.h>
//#include<ext/pb_ds/assoc_container.hpp>
//#include<ext/pb_ds/tree_policy.hpp>

#define pb push_back
#define mp make_pair

#define all(x) (x).begin(), (x).end()

#define fi first
#define se second

using namespace std;
//using namespace __gnu_pbds;

typedef long long ll;   
typedef pair<int, int> pii;
//template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const int MAXN = (int)2e2 + 5;
const int MOD = (int)1e9 + 7;

int fact[MAXN], rev[MAXN];

int dp[MAXN][MAXN][MAXN];

int mem[MAXN][MAXN];

vector<int> T;

pii arr[MAXN];

int n;

int addMod(int a, int b, int m = MOD) {
    a += b;

    if (m <= a) {
        a -= m;
    }
    
    return a;
}

int mulMod(int a, int b, int m = MOD) {
    return a * 1ll * b % m;
}

int binPow(int a, int b, int m = MOD) {
    int ret = 1;

    while (b > 0) {
        if (b & 1) {
            ret = mulMod(ret, a, m);
        }

        a = mulMod(a, a, m);
        b >>= 1;
    }

    return ret;
}

void pre() {
    fact[0] = rev[0] = 1;

    for (int i = 1; i < MAXN; ++i) {
        fact[i] = mulMod(fact[i - 1], i);
        rev[i] = binPow(fact[i], MOD - 2);
    }
}

int C(int n, int k) {
    if (n < 0 || k < 0 || k > n) {
        return 0;
    }

    int a = 1, b = 1;

    for (int i = n - k + 1; i <= n; ++i) {
        a = mulMod(a, i);
    }

    for (int i = 1; i <= k; ++i) {
        b = mulMod(b, i);
    }                        

    return mulMod(a, binPow(b, MOD - 2));
}

int f(int idx, int cnt) {
    int x = T[idx + 1] - T[idx];
    return C(x, cnt);
}

void solve() {
    scanf("%d", &n);

    for (int i = 1; i <= n; ++i) {
        scanf("%d %d", &arr[i].fi, &arr[i].se);
        T.pb(arr[i].fi);
        T.pb(arr[i].se + 1);
    }

    T.pb(0);
    sort(all(T));
    T.resize(unique(all(T)) - T.begin());

    for (int i = 1; i <= n; ++i) {
        arr[i].fi = lower_bound(all(T), arr[i].fi) - T.begin();
        arr[i].se = lower_bound(all(T), arr[i].se + 1) - T.begin();
    }

    for (int i = 0; i + 1 < T.size(); ++i) {
        for (int j = 0; j <= n; ++j) {
            mem[i][j] = f(i, j);
        }
    }    

    dp[0][0][0] = 1;

    for (int i = 1; i <= n; ++i) {
        for (int c = 0; c < T.size(); ++c) {
            for (int cnt = 0; cnt <= n; ++cnt) {
                dp[i][c][cnt] = dp[i - 1][c][cnt];
            }
        }

        int p = 0, w = 0;

        for (int c = arr[i].fi; c < arr[i].se; ++c) {
            for (int cnt = 1; cnt <= n; ++cnt) {
                dp[i][c][cnt] = addMod(dp[i][c][cnt], dp[i - 1][c][cnt - 1]);                                                                
            }

            while (p < c) {
                for (int cnt = 0; cnt <= n; ++cnt) {
                    w = addMod(w, mulMod(dp[i - 1][p][cnt], mem[p][cnt]));
                }

                ++p;
            }

            dp[i][c][1] = addMod(dp[i][c][1], w);
        }
    }

    int ans = 0;

    for (int c = 0; c + 1 < T.size(); ++c) {
        for (int cnt = 1; cnt <= n; ++cnt) {
            ans = addMod(ans, mulMod(dp[n][c][cnt], mem[c][cnt]));            
        }
    }        

    printf("%d\n", ans);
}

int main() {
    int tt = 1;

    pre();

    while (tt--) {
        solve();
    }

    return 0;
}

Compilation message

boat.cpp: In function 'void solve()':
boat.cpp:117:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i + 1 < T.size(); ++i) {
                     ~~~~~~^~~~~~~~~~
boat.cpp:126:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int c = 0; c < T.size(); ++c) {
                         ~~^~~~~~~~~~
boat.cpp:153:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int c = 0; c + 1 < T.size(); ++c) {
                     ~~~~~~^~~~~~~~~~
boat.cpp:100:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
boat.cpp:103:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &arr[i].fi, &arr[i].se);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Runtime error 7 ms 504 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Runtime error 7 ms 504 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 17016 KB Output is correct
2 Correct 34 ms 16888 KB Output is correct
3 Correct 35 ms 16948 KB Output is correct
4 Correct 36 ms 17036 KB Output is correct
5 Correct 35 ms 16888 KB Output is correct
6 Correct 36 ms 17016 KB Output is correct
7 Correct 39 ms 16888 KB Output is correct
8 Correct 37 ms 16888 KB Output is correct
9 Correct 39 ms 16888 KB Output is correct
10 Correct 36 ms 16888 KB Output is correct
11 Correct 39 ms 16888 KB Output is correct
12 Correct 35 ms 17016 KB Output is correct
13 Correct 37 ms 16888 KB Output is correct
14 Correct 35 ms 16888 KB Output is correct
15 Correct 35 ms 16888 KB Output is correct
16 Correct 20 ms 10232 KB Output is correct
17 Correct 20 ms 9976 KB Output is correct
18 Correct 20 ms 9976 KB Output is correct
19 Correct 20 ms 10108 KB Output is correct
20 Correct 20 ms 9720 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Runtime error 7 ms 504 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -