Submission #1234293

#	Time	Username	Problem	Language	Result	Execution time	Memory
1234293		badge881	Street Lamps (APIO19_street_lamps)	C++20	20 / 100	177 ms	6968 KiB

street_lamps

#include <bits/stdc++.h>
using namespace std;

const int INF = 2147483647;

class SegTree
{
    int n;
    vector<int> s;

    void update(int pos, int val, int node, int low, int high)
    {
        if (low == high - 1)
        {
            s[node] = val;
            return;
        }
        int m = (low + high) / 2;
        if (pos < m)
            update(pos, val, 2 * node, low, m);
        else
            update(pos, val, 2 * node + 1, m, high);
        s[node] = max(s[2 * node], s[2 * node + 1]);
    }

    int query(int l, int r, int node, int low, int high)
    {
        if (r <= low || high <= l)
            return 0;
        if (l <= low && high <= r)
            return s[node];
        int m = (low + high) / 2;
        return max(query(l, r, 2 * node, low, m), query(l, r, 2 * node + 1, m, high));
    }

public:
    SegTree(int n) : n(n), s(4 * n, 0) {}

    void update(int pos, int val)
    {
        update(pos, val, 1, 0, n);
    }
    int query(int deb, int fin)
    {
        // [deb, fin)
        if (deb >= fin)
            return 0;
        return query(deb, fin, 1, 0, n);
    }
};

signed main()
{
    int n, q;
    scanf("%d%d\n", &n, &q);
    SegTree seg(n);
    for (int i = 0; i < n; i++)
    {
        char chr;
        scanf("\n%c\n", &chr);
        seg.update(i, chr == '1' ? 0 : INF);
    }
    int time = 1;
    for (int i = 0; i < q; i++)
    {
        char str[10];
        scanf("\n%s ", str);
        if (str[0] == 't')
        {
            int i;
            scanf("%d\n", &i);
            i--;
            seg.update(i, time);
        }
        else
        {
            int l, r;
            scanf("%d%d\n", &l, &r);
            int last = seg.query(l - 1, r - 1);
            if (last == INF)
                printf("0\n");
            else
                printf("%d\n", time - last);
        }

        time++;
    }
    return 0;
}

Compilation message (stderr)

street_lamps.cpp: In function 'int main()':
street_lamps.cpp:55:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 |     scanf("%d%d\n", &n, &q);
      |     ~~~~~^~~~~~~~~~~~~~~~~~
street_lamps.cpp:60:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |         scanf("\n%c\n", &chr);
      |         ~~~~~^~~~~~~~~~~~~~~~
street_lamps.cpp:67:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |         scanf("\n%s ", str);
      |         ~~~~~^~~~~~~~~~~~~~
street_lamps.cpp:71:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   71 |             scanf("%d\n", &i);
      |             ~~~~~^~~~~~~~~~~~
street_lamps.cpp:78:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |             scanf("%d%d\n", &l, &r);
      |             ~~~~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 20
• Subtask 2: 0 / 20
• Subtask 3: 20 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 20