Submission #690874

#	Time	Username	Problem	Language	Result	Execution time	Memory
690874		drdilyor	Bigger segments (IZhO19_segments)	C++17	0 / 100	1 ms	328 KiB

segments

#include <bits/stdc++.h>
#ifdef ONPC
    #include "t_debug.cpp"
#else
    #define debug(...) 42
#endif
using namespace std;
//namespace pbds = __gnu_pbds;
using ll = long long;
const int inf = 1e9;
const ll infl = 1e18;
const int RANDOM = chrono::high_resolution_clock::now().time_since_epoch().count();
mt19937 rng(RANDOM);
template<typename T, typename U> istream& operator>>(istream& is, pair<T, U>& p) { return is >> p.first >> p.second; }
template<typename Cont> int sz(const Cont& cont) { return int(cont.size()); }
const string fileio = "";
constexpr int tests = 0, nmax = 2e5, nlog = __lg(nmax), mod = 1e9+7;

int solve() {
    int n; cin >> n;
    vector<int> arr(n);
    for (auto& i : arr) {cin >> i;}
    vector<ll> pref(n+1);
    for (int i = 0; i < n; i++)
        pref[i+1] = pref[i] + arr[i];

    vector<ll> dp(n+1), cnt(n+1);
    pair a = {-1, -1}, b{0, -1};
    for (int i = 0; i < n ;i++) {
        ll s = 0;
        auto check = [&](int j)->bool {
            if (pref[i+1] - pref[j] >= dp[j]) {
                return true;
            }
            return false;
        };
        auto search = [&](int lb, int rb) {
            bool found = 1;
            lb--; rb++;
            while (lb < rb-1) {
                int m = (lb+rb) / 2;
                if (check(m)) {found = 1; lb = m;}
                else rb =m;
            }
            if (found) {
                dp[i+1] = pref[i+1] - pref[lb];
                cnt[i+1] = cnt[lb]+1;
            }
        };
        dp[i+1] = pref[i+1];
        cnt[i+1] = 1;
        int x = cnt[i];
        auto [l, r] = equal_range(cnt.begin(), cnt.begin()+i+1, cnt[i]);
        assert(r == cnt.begin()+i+1);
        auto [l1, r1] = equal_range(cnt.begin(), cnt.begin()+i+1, cnt[i]-1);
        assert(r1 == l);
        search(l1-cnt.begin(), r1-cnt.begin());
        search(l-cnt.begin(), r-cnt.begin());
    }
    debug(dp);
    debug(cnt);
    cout << cnt.back() << '\n';

    return 0;
}

signed main() {
    int t = 1;
    #ifdef ONPC
    t = 10000;
    #else
    if (fileio.size()) {freopen((fileio+".in").c_str(),"r",stdin);freopen((fileio+".out").c_str(),"w",stdout);}
    #endif
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit | cin.eofbit);
    cout << fixed << setprecision(8);
    if (tests) cin >> t;
    while (t-- && cin) {
        if (solve()) break;
        #ifdef ONPC
            cout << "____________________" << endl;
        #endif
    }
    return 0;
}

/*
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▒███ ▒███  ▒███ ▒▒▒ ▒███ ▒███  ▒███  ▒███  ▒███ ▒███ ▒███ ▒███ ▒███ ▒▒▒ 
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▒▒████████ █████    ▒▒████████ █████ █████ ▒▒███████ ▒▒██████  █████    
 ▒▒▒▒▒▒▒▒ ▒▒▒▒▒      ▒▒▒▒▒▒▒▒ ▒▒▒▒▒ ▒▒▒▒▒   ▒▒▒▒▒███  ▒▒▒▒▒▒  ▒▒▒▒▒     
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*/

Compilation message (stderr)

segments.cpp: In function 'int solve()':
segments.cpp:30:12: warning: unused variable 's' [-Wunused-variable]
   30 |         ll s = 0;
      |            ^
segments.cpp:52:13: warning: unused variable 'x' [-Wunused-variable]
   52 |         int x = cnt[i];
      |             ^
segments.cpp:5:24: warning: statement has no effect [-Wunused-value]
    5 |     #define debug(...) 42
      |                        ^~
segments.cpp:60:5: note: in expansion of macro 'debug'
   60 |     debug(dp);
      |     ^~~~~
segments.cpp:5:24: warning: statement has no effect [-Wunused-value]
    5 |     #define debug(...) 42
      |                        ^~
segments.cpp:61:5: note: in expansion of macro 'debug'
   61 |     debug(cnt);
      |     ^~~~~
segments.cpp:28:10: warning: variable 'a' set but not used [-Wunused-but-set-variable]
   28 |     pair a = {-1, -1}, b{0, -1};
      |          ^
segments.cpp: In function 'int main()':
segments.cpp:72:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |     if (fileio.size()) {freopen((fileio+".in").c_str(),"r",stdin);freopen((fileio+".out").c_str(),"w",stdout);}
      |                         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
segments.cpp:72:74: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |     if (fileio.size()) {freopen((fileio+".in").c_str(),"r",stdin);freopen((fileio+".out").c_str(),"w",stdout);}
      |                                                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 13
• Subtask 2: 0 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27