Submission #689428

#	Time	Username	Problem	Language	Result	Execution time	Memory
689428		Matteo_Verz	Bigger segments (IZhO19_segments)	C++17	13 / 100	1 ms	212 KiB

segments

    #include <bits/stdc++.h>
    #ifdef BLAT
        #include "debug/debug.hpp"
    #else
        #define debug(x...)
    #endif
     
    using namespace std;
     
    const long long INF = 1'000'000'000'000'000; // 1e15
     
    int binSearch(const vector <long long> &v, int val) {
        int r, pas;
        for (r = -1, pas = 1 << 17; pas; pas >>= 1)
            if (r + pas < v.size() && v[r + pas] < val)
                r += pas;
        r++;
     
        return r;
    }
     
    int main() {
        ios_base::sync_with_stdio(false);
        cin.tie(nullptr);
        int n;
        cin >> n;
     
        vector <int> v(1 + n), dp(1 + n);
        vector <long long> sp(1 + n), s(1 + n, INF);
     
        for (int i = 1; i <= n; i++) {
            cin >> v[i];
            sp[i] = sp[i - 1] + v[i];
        }
     
        dp[1] = 1;
        s[1] = sp[1];
        for (int i = 1; i <= n; i++) {
            dp[i] = max(dp[i], dp[i - 1]);
            s[i] = min(s[i], s[i - 1] + v[i]);
     
            int pos = binSearch(sp, s[i] + sp[i]);
            if (pos > n) continue;
     
            if (dp[pos] == dp[i] + 1)
                s[pos] = min(s[pos], sp[pos] - sp[i]);
            else if (dp[pos] < dp[i] + 1) {
                s[pos] = sp[pos] - sp[i];
                dp[pos] = 1 + dp[i];
            }
        }
        
        cout << dp[n] << '\n';
        return 0;
    }

Compilation message (stderr)

segments.cpp: In function 'int binSearch(const std::vector<long long int>&, int)':
segments.cpp:15:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |             if (r + pas < v.size() && v[r + pas] < val)
      |                 ~~~~~~~~^~~~~~~~~~

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