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답안 #218039

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
218039 2020-03-31T14:31:35 Z perveevm Boat (APIO16_boat) C++14
100 / 100
 584 ms 2560 KB 
// #pragma comment(linker, "/stack:200000000")
// #pragma GCC optimize("Ofast,no-stack-protector")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
// #pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>

#ifdef PERVEEVM_LOCAL
    #define debug(x) std::cerr << (#x) << ":\t" << (x) << std::endl
#else
    #define debug(x) 238;
#endif

#define fastIO std::ios_base::sync_with_stdio(false); std::cin.tie(0); std::cout.tie(0)
#define NAME "File"

using ll = long long;
using ld = long double;

#ifdef PERVEEVM_LOCAL
    std::mt19937 rnd(238);
#else
    std::mt19937 rnd(std::chrono::high_resolution_clock::now().time_since_epoch().count());
#endif

const double PI = atan2(0.0, -1.0);
const int INF = 0x3f3f3f3f;
const ll LINF = (ll)2e18;
const int N = 510;
const int MOD = (int)1e9 + 7;

int add(int a, int b, int mod = MOD) {
    if (a + b >= mod) {
        return a + b - mod;
    }
    return a + b;
}

int sub(int a, int b, int mod = MOD) {
    if (a - b < 0) {
        return a - b + mod;
    }
    return a - b;
}

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

int binpow(int a, int n, int mod = MOD) {
    if (n == 0) {
        return 1;
    }
    if (n % 2 == 0) {
        return binpow(mul(a, a, mod), n / 2, mod);
    } else {
        return mul(binpow(a, n - 1, mod), a, mod);
    }
}

int rev(int a, int mod = MOD) {
    return binpow(a, mod - 2, mod);
}

int a[N], b[N];
int dp[2 * N][N];
int f[2 * N], rf[2 * N];
int r[2 * N];

void precalc() {
    f[0] = 1;
    rf[0] = 1;

    for (int i = 1; i < 2 * N; ++i) {
        f[i] = mul(f[i - 1], i);
        rf[i] = rev(f[i]);
        r[i] = rev(i);
    }
}

int C(int n, int k) {
    if (n < k) {
        return 0;
    }
    return mul(f[n], mul(rf[k], rf[n - k]));
}

void run() {
    precalc();

    int n;
    scanf("%d", &n);

    for (int i = 1; i <= n; ++i) {
        scanf("%d%d", &a[i], &b[i]);
        ++b[i];
    }

    std::vector<int> trans;
    for (int i = 1; i <= n; ++i) {
        trans.push_back(a[i]);
        trans.push_back(b[i]);
    }

    std::sort(trans.begin(), trans.end());
    trans.resize(std::unique(trans.begin(), trans.end()) - trans.begin());

    for (int i = 1; i <= n; ++i) {
        a[i] = std::lower_bound(trans.begin(), trans.end(), a[i]) - trans.begin() + 1;
        b[i] = std::lower_bound(trans.begin(), trans.end(), b[i]) - trans.begin() + 1;
    }

    dp[0][0] = 1;
    // dp[i][j] - ans if last segment is i'th or less and last boat is j'th

    for (int i = 1; i < (int)trans.size(); ++i) {
        dp[i][0] = 1;

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

            if (i < a[j] || b[j] <= i) {
                continue;
            }

            int len = trans[i] - trans[i - 1];

            int curC = len;
            int cnt = 1;

            for (int k = j - 1; k >= 0; --k) {
                dp[i][j] = add(dp[i][j], mul(dp[i - 1][k], curC));

                if (a[k] <= i && i < b[k]) {
                    ++cnt;
                    curC = mul(curC, len + cnt - 1);
                    curC = mul(curC, r[cnt]);
                }
            }
        }
    }

    int ans = 0;
    for (int i = 1; i <= n; ++i) {
        ans = add(ans, dp[(int)trans.size() - 1][i]);
    }

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

int main(void) {
    // freopen(NAME".in", "r", stdin);
    // freopen(NAME".out", "w", stdout);

    auto start = std::chrono::high_resolution_clock::now();
    run();
    auto end = std::chrono::high_resolution_clock::now();

    #ifdef PERVEEVM_LOCAL
        std::cerr << "Execution time: "
                  << std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count()
                  << " ms" << std::endl;
    #endif

    return 0;
}

Compilation message

boat.cpp: In function 'int main()':
boat.cpp:155:10: warning: variable 'start' set but not used [-Wunused-but-set-variable]
     auto start = std::chrono::high_resolution_clock::now();
          ^~~~~
boat.cpp:157:10: warning: variable 'end' set but not used [-Wunused-but-set-variable]
     auto end = std::chrono::high_resolution_clock::now();
          ^~~
boat.cpp: In function 'void run()':
boat.cpp:92:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
boat.cpp:95:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &a[i], &b[i]);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 8 ms 2304 KB Output is correct
2 Correct 8 ms 2304 KB Output is correct
3 Correct 8 ms 2304 KB Output is correct
4 Correct 8 ms 2304 KB Output is correct
5 Correct 9 ms 2304 KB Output is correct
6 Correct 8 ms 2304 KB Output is correct
7 Correct 7 ms 2304 KB Output is correct
8 Correct 8 ms 2304 KB Output is correct
9 Correct 8 ms 2304 KB Output is correct
10 Correct 8 ms 2304 KB Output is correct
11 Correct 9 ms 2304 KB Output is correct
12 Correct 9 ms 2304 KB Output is correct
13 Correct 8 ms 2304 KB Output is correct
14 Correct 8 ms 2304 KB Output is correct
15 Correct 8 ms 2304 KB Output is correct
16 Correct 7 ms 640 KB Output is correct
17 Correct 7 ms 768 KB Output is correct
18 Correct 7 ms 768 KB Output is correct
19 Correct 7 ms 768 KB Output is correct
20 Correct 7 ms 768 KB Output is correct

Subtask #2
22.0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 8 ms 2304 KB Output is correct
2 Correct 8 ms 2304 KB Output is correct
3 Correct 8 ms 2304 KB Output is correct
4 Correct 8 ms 2304 KB Output is correct
5 Correct 9 ms 2304 KB Output is correct
6 Correct 8 ms 2304 KB Output is correct
7 Correct 7 ms 2304 KB Output is correct
8 Correct 8 ms 2304 KB Output is correct
9 Correct 8 ms 2304 KB Output is correct
10 Correct 8 ms 2304 KB Output is correct
11 Correct 9 ms 2304 KB Output is correct
12 Correct 9 ms 2304 KB Output is correct
13 Correct 8 ms 2304 KB Output is correct
14 Correct 8 ms 2304 KB Output is correct
15 Correct 8 ms 2304 KB Output is correct
16 Correct 7 ms 640 KB Output is correct
17 Correct 7 ms 768 KB Output is correct
18 Correct 7 ms 768 KB Output is correct
19 Correct 7 ms 768 KB Output is correct
20 Correct 7 ms 768 KB Output is correct
21 Correct 288 ms 2176 KB Output is correct
22 Correct 259 ms 2168 KB Output is correct
23 Correct 242 ms 2168 KB Output is correct
24 Correct 258 ms 2168 KB Output is correct
25 Correct 267 ms 2144 KB Output is correct
26 Correct 504 ms 2232 KB Output is correct
27 Correct 516 ms 2168 KB Output is correct
28 Correct 504 ms 2040 KB Output is correct
29 Correct 501 ms 2296 KB Output is correct
30 Correct 9 ms 2304 KB Output is correct
31 Correct 9 ms 2304 KB Output is correct
32 Correct 8 ms 2304 KB Output is correct
33 Correct 9 ms 2304 KB Output is correct
34 Correct 9 ms 2304 KB Output is correct
35 Correct 9 ms 2304 KB Output is correct
36 Correct 10 ms 2432 KB Output is correct
37 Correct 9 ms 2304 KB Output is correct
38 Correct 10 ms 2304 KB Output is correct

Subtask #3
27.0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 8 ms 768 KB Output is correct
2 Correct 7 ms 768 KB Output is correct
3 Correct 8 ms 768 KB Output is correct
4 Correct 8 ms 768 KB Output is correct
5 Correct 8 ms 768 KB Output is correct
6 Correct 10 ms 768 KB Output is correct
7 Correct 10 ms 768 KB Output is correct
8 Correct 11 ms 768 KB Output is correct
9 Correct 10 ms 768 KB Output is correct
10 Correct 10 ms 768 KB Output is correct
11 Correct 8 ms 768 KB Output is correct
12 Correct 7 ms 768 KB Output is correct
13 Correct 8 ms 768 KB Output is correct
14 Correct 8 ms 768 KB Output is correct
15 Correct 8 ms 768 KB Output is correct
16 Correct 7 ms 640 KB Output is correct
17 Correct 7 ms 512 KB Output is correct
18 Correct 7 ms 512 KB Output is correct
19 Correct 7 ms 512 KB Output is correct
20 Correct 7 ms 512 KB Output is correct

Subtask #4
42.0 / 42.0

# 결과 실행 시간 메모리 Grader output
1 Correct 8 ms 2304 KB Output is correct
2 Correct 8 ms 2304 KB Output is correct
3 Correct 8 ms 2304 KB Output is correct
4 Correct 8 ms 2304 KB Output is correct
5 Correct 9 ms 2304 KB Output is correct
6 Correct 8 ms 2304 KB Output is correct
7 Correct 7 ms 2304 KB Output is correct
8 Correct 8 ms 2304 KB Output is correct
9 Correct 8 ms 2304 KB Output is correct
10 Correct 8 ms 2304 KB Output is correct
11 Correct 9 ms 2304 KB Output is correct
12 Correct 9 ms 2304 KB Output is correct
13 Correct 8 ms 2304 KB Output is correct
14 Correct 8 ms 2304 KB Output is correct
15 Correct 8 ms 2304 KB Output is correct
16 Correct 7 ms 640 KB Output is correct
17 Correct 7 ms 768 KB Output is correct
18 Correct 7 ms 768 KB Output is correct
19 Correct 7 ms 768 KB Output is correct
20 Correct 7 ms 768 KB Output is correct
21 Correct 288 ms 2176 KB Output is correct
22 Correct 259 ms 2168 KB Output is correct
23 Correct 242 ms 2168 KB Output is correct
24 Correct 258 ms 2168 KB Output is correct
25 Correct 267 ms 2144 KB Output is correct
26 Correct 504 ms 2232 KB Output is correct
27 Correct 516 ms 2168 KB Output is correct
28 Correct 504 ms 2040 KB Output is correct
29 Correct 501 ms 2296 KB Output is correct
30 Correct 9 ms 2304 KB Output is correct
31 Correct 9 ms 2304 KB Output is correct
32 Correct 8 ms 2304 KB Output is correct
33 Correct 9 ms 2304 KB Output is correct
34 Correct 9 ms 2304 KB Output is correct
35 Correct 9 ms 2304 KB Output is correct
36 Correct 10 ms 2432 KB Output is correct
37 Correct 9 ms 2304 KB Output is correct
38 Correct 10 ms 2304 KB Output is correct
39 Correct 8 ms 768 KB Output is correct
40 Correct 7 ms 768 KB Output is correct
41 Correct 8 ms 768 KB Output is correct
42 Correct 8 ms 768 KB Output is correct
43 Correct 8 ms 768 KB Output is correct
44 Correct 10 ms 768 KB Output is correct
45 Correct 10 ms 768 KB Output is correct
46 Correct 11 ms 768 KB Output is correct
47 Correct 10 ms 768 KB Output is correct
48 Correct 10 ms 768 KB Output is correct
49 Correct 8 ms 768 KB Output is correct
50 Correct 7 ms 768 KB Output is correct
51 Correct 8 ms 768 KB Output is correct
52 Correct 8 ms 768 KB Output is correct
53 Correct 8 ms 768 KB Output is correct
54 Correct 7 ms 640 KB Output is correct
55 Correct 7 ms 512 KB Output is correct
56 Correct 7 ms 512 KB Output is correct
57 Correct 7 ms 512 KB Output is correct
58 Correct 7 ms 512 KB Output is correct
59 Correct 297 ms 2556 KB Output is correct
60 Correct 273 ms 2296 KB Output is correct
61 Correct 254 ms 2296 KB Output is correct
62 Correct 299 ms 2296 KB Output is correct
63 Correct 282 ms 2296 KB Output is correct
64 Correct 584 ms 2484 KB Output is correct
65 Correct 579 ms 2424 KB Output is correct
66 Correct 581 ms 2560 KB Output is correct
67 Correct 577 ms 2424 KB Output is correct
68 Correct 578 ms 2424 KB Output is correct
69 Correct 240 ms 2296 KB Output is correct
70 Correct 243 ms 2296 KB Output is correct
71 Correct 241 ms 2356 KB Output is correct
72 Correct 249 ms 2300 KB Output is correct
73 Correct 253 ms 2296 KB Output is correct
74 Correct 62 ms 760 KB Output is correct
75 Correct 60 ms 760 KB Output is correct
76 Correct 61 ms 760 KB Output is correct
77 Correct 62 ms 760 KB Output is correct
78 Correct 63 ms 760 KB Output is correct