Submission #870003

#	Time	Username	Problem	Language	Result	Execution time	Memory
870003		Alora	Street Lamps (APIO19_street_lamps)	C++17	20 / 100	179 ms	13088 KiB

street_lamps

#include <bits/stdc++.h>
#define Alora "cownav"
#define fi(i,a,b) for(int i = a; i <= b; i++)
#define fid(i,a,b) for(int i = a; i >= b; i--)
#define ll long long
#define f first
#define se second
#define pii pair<int, int>
#define getbit(i, j) ((i >> j) & 1)
#define all(v) v.begin(), v.end()
#define pb push_back
#define maxn 300005
const int M = 1e9 + 7;
using namespace std;
int n, m, st[maxn*4];
string s;

void build(int id, int l, int r){
    if(l == r){
        if(s[l] == '1') st[id] = 0;
        else st[id] = 1e9;
        return;
    }
    int m = (l + r)/2;
    build(id*2, l, m);
    build(id*2 + 1, m + 1, r);
    st[id] = max(st[id*2], st[id*2 + 1]);
}

void ud(int id, int l, int r, int u, int x){
    if(l > u || r < u) return;
    if(l == r) {st[id] = x; return;}
    int m = (l + r)/2;
    ud(id*2, l, m, u, x);
    ud(id*2 + 1, m + 1, r, u, x);
    st[id] = max(st[id*2], st[id*2 + 1]);
}

int get(int id, int l, int r, int u, int v){
    if(l > v || r < u) return 0;
    if(u <= l && r <= v) return st[id];
    int m = (l + r)/2;
    return max(get(id*2, l, m, u, v), get(id*2 + 1, m + 1, r, u, v));
}

int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(NULL);
	if(fopen(Alora".inp","r")){
    freopen(Alora".inp","r",stdin);
    freopen(Alora".out","w",stdout);}
    cin >> n >> m;
    cin >> s; s = ' ' + s;
    build(1, 1, n);
    fi(i, 1, m){
        string c; cin >> c;
        if(c == "toggle"){
            int x; cin >> x;
            ud(1, 1, n, x, i);
        }
        else{
            int a, b; cin >> a >> b;
            int x = get(1, 1, n, a, b - 1);
            if(x == 1e9) cout << 0 << '\n';
            else cout << i - x << '\n';
        }
    }
    return 0;
}

Compilation message (stderr)

street_lamps.cpp: In function 'int main()':
street_lamps.cpp:50:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |     freopen(Alora".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
street_lamps.cpp:51:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |     freopen(Alora".out","w",stdout);}
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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