Submission #624397

#	Time	Username	Problem	Language	Result	Execution time	Memory
624397		boris_mihov	Sum Zero (RMI20_sumzero)	C++14	0 / 100	3 ms	724 KiB

sumzero

#include <unordered_map>
#include <algorithm>
#include <iostream>
#include <cassert>
#include <numeric>
#include <vector>

typedef long long llong;
const int MAXN = 400000 + 10;
const int MAXLOG = 10;
const int BASE = 2;

std::unordered_map < llong,int > cnt;
int sparse[MAXLOG][MAXN];
int n, q;

void buildSparse()
{
    for (int log = 1 ; log <= MAXLOG-1 ; ++log)
    {
        sparse[log][0] = -1;
        for (int i = 1 ; i <= n ; ++i)
        {
            sparse[log][i] = i;
            for (int j = 1 ; j <= BASE ; ++j)
            {
                sparse[log][i] = sparse[log-1][sparse[log][i]];
                if (sparse[log][i] == -1) break;
            }
        }
    }
}

int lifting(int from, int to)
{
    int ans = 0;
    int pw = (1 << MAXLOG-1);
    for (int log = MAXLOG-1 ; log >= 0 ; --log)
    {
        while (sparse[log][from] >= to-1)
        {
            ans += pw;
            from = sparse[log][from];
        }
    
        pw /= BASE;
    }

    return ans;
}

void solve()
{
    int l, r;
    buildSparse();
    std::cin >> q;
    for (int i = 1 ; i <= q ; ++i)
    {
        std::cin >> l >> r;
        std::cout << lifting(r, l) << '\n';
    }
}

void read()
{
    cnt[0] = 1;
    sparse[0][0] = -1;

    int curr;
    llong sum;
    std::cin >> n;
    for (int i = 1 ; i <= n ; ++i)
    {
        std::cin >> curr;
        sum += curr;

        sparse[0][i] = std::max(sparse[0][i-1], cnt[sum] - 1);
        cnt[sum] = i + 1;
    }
}

void fastIO()
{
    std::ios_base :: sync_with_stdio(0);
    std::cout.tie(nullptr);
    std::cin.tie(nullptr);
}

int main()
{
    fastIO();
    read();
    solve();

    return 0;
}

Compilation message (stderr)

sumzero.cpp: In function 'int lifting(int, int)':
sumzero.cpp:37:26: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   37 |     int pw = (1 << MAXLOG-1);
      |                    ~~~~~~^~

• Subtask 1: 0 / 22
• Subtask 2: 0 / 39
• Subtask 3: 0 / 39