Submission #885738

#	Time	Username	Problem	Language	Result	Execution time	Memory
885738		fanwen	Street Lamps (APIO19_street_lamps)	C++17	20 / 100	5069 ms	524288 KiB

street_lamps

#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define ll long long
#define file(name)                  \
    if(fopen(name".inp", "r"))      \
        freopen(name".inp", "r", stdin), freopen(name".out", "w", stdout); \

void you_make_it(void) {
	int n, q; cin >> n >> q;
	vector <vector <int>> a(q, vector <int> (n));
	vector <vector <int>> pref(q, vector <int> (n));
	for (int i = 0; i < n; ++i) {
		char x; cin >> x;
		a[0][i] = x - '0';
	}

	for (int i = 0; i < q; ++i) {
		string s; cin >> s;
		if(i > 0) a[i] = a[i - 1];
		for (int j = 0; j < n; ++j) {
			pref[i][j] = (j == 0 ? 0 : pref[i][j - 1]) + a[i][j];
		}
		if(s == "toggle") {
			int p; cin >> p; p--;
			a[i][p] ^= 1;
		}
		if(s == "query") {
			int l, r; cin >> l >> r;
			l--, r--;
			int ans = 0;
			for (int t = 0; t <= i; t++) {
				if(pref[t][r - 1] - (l == 0 ? 0 : pref[t][l - 1]) == r - l) ans++;
			}
			cout << ans << '\n';
		}
	}

	// for (int i = 0; i < q; ++i) {
	// 	for (int j = 0; j < n; ++j) cout << a[i][j] << " \n"[j == n - 1];
	// }
}

signed main() {

#ifdef LOCAL
    freopen("TASK.inp", "r", stdin);
    freopen("TASK.out", "w", stdout);
#endif
    file("street_lamps");
    auto start_time = chrono::steady_clock::now();

    cin.tie(0), cout.tie(0) -> sync_with_stdio(0);

    you_make_it();

    auto end_time = chrono::steady_clock::now();

    cerr << "\nExecution time : " << chrono::duration_cast <chrono::milliseconds> (end_time - start_time).count() << "[ms]" << endl;

    return (0 ^ 0);
}

// Dream it. Wish it. Do it.

Compilation message (stderr)

street_lamps.cpp: In function 'int main()':
street_lamps.cpp:10:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |         freopen(name".inp", "r", stdin), freopen(name".out", "w", stdout); \
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
street_lamps.cpp:53:5: note: in expansion of macro 'file'
   53 |     file("street_lamps");
      |     ^~~~
street_lamps.cpp:10:49: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |         freopen(name".inp", "r", stdin), freopen(name".out", "w", stdout); \
      |                                          ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
street_lamps.cpp:53:5: note: in expansion of macro 'file'
   53 |     file("street_lamps");
      |     ^~~~

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