Submission #1122937

#	Time	Username	Problem	Language	Result	Execution time	Memory
1122937		gdragon	Boat (APIO16_boat)	C++20	0 / 100	76 ms	1444 KiB

boat

#include <bits/stdc++.h>
using namespace std;
#define TASK "long"
#define fi first
#define se second
#define ll long long
#define pb push_back
#define ALL(x) (x).begin(), (x).end()
#define GETBIT(mask, i) ((mask) >> (i) & 1)
#define MASK(i) ((1LL) << (i))
#define SZ(x) ((int)(x).size())
#define mp make_pair
#define CNTBIT(mask) __builtin_popcount(mask)
template<class X, class Y> bool maximize(X &x, Y y){ if (x < y) {x = y; return true;} return false;};
template<class X, class Y> bool minimize(X &x, Y y){ if (x > y) {x = y; return true;} return false;};
typedef pair<int, int> ii;
const int N = 500 + 5;
const int inf = 1e9 + 7;
const long long INF = (long long)1e18 + 7;
const int mod = 1e9 + 7;
void add(int &x, int y) {x += y; if (x >= mod) x -= mod;}
void sub(int &x, int y) {x -= y; if (x < 0) x += mod;}
int mul(int x, int y) {return 1LL * x * y % mod;}
// -----------------------------------------//
int n;
int a[N], b[N];
void read() {
    cin >> n;
    for(int i = 1; i <= n; i++) cin >> a[i] >> b[i];
}
void sub1() {
    vector<vector<int>> dp;
    dp.assign(n + 2, vector<int>(n + 2, 0));
    dp[0][0] = 1;
    for(int i = 1; i <= n; i++) {
        dp[i][1] = 1;
        for(int j = 2; j <= i; j++) {
            for(int k = i - 1; k >= 1; k--) {
                if (a[i] >= a[k]) add(dp[i][j], dp[k][j - 1]);
            }
        }
    }
    int ans = 0;
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= i; j++) add(ans, dp[i][j]);
    }
    cout << ans;
}
void solve() {
    auto check1 = [&] () -> bool {
        bool ok = 1;
        for(int i = 1; i <= n; i++) ok &= (a[i] == b[i]);
        return ok;
    }; 
    if (check1()) sub1(); 
}
signed main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }
    int test = 1;
    // cin >> test;
    while(test--) {
        read();
        solve();
    }
    return 0;
}

Compilation message (stderr)

boat.cpp: In function 'int main()':
boat.cpp:60:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
boat.cpp:61:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 9
• Subtask 2: 0 / 22
• Subtask 3: 0 / 27
• Subtask 4: 0 / 42