Submission #597336

#	Time	Username	Problem	Language	Result	Execution time	Memory
597336		pedroslrey	Sum Zero (RMI20_sumzero)	C++17	61 / 100	422 ms	41476 KiB

sumzero

#include <bits/stdc++.h>

using namespace std;
using lli = long long;

const int MAXN = 4e5 + 10;
const int MAXK = 20;

int ant[MAXN];
int dp[MAXN][MAXK];

int main() {
	int n;
	scanf("%d", &n);

	vector<pair<lli, int>> xs{{0, 0}};
	lli sum = 0;
	for (int i = 1; i <= n; ++i) {
		int x;
		scanf("%d", &x);

		sum += x;
		xs.emplace_back(sum, i);
	}

	for (int i = 1; i <= n; ++i)
		ant[i] = -1;

	sort(xs.begin(), xs.end());
	for (int i = 1; i <= n; ++i)
		if (xs[i].first == xs[i-1].first)
			ant[xs[i].second] = xs[i-1].second;

	for (int k = 0; k < MAXK; ++k)
		dp[0][k] = -1;

	for (int i = 1; i <= n; ++i) {
		if (ant[i] < dp[i-1][0]) dp[i][0] = dp[i-1][0];
		else dp[i][0] = ant[i];

		for (int k = 1; k < MAXK; ++k)
			if (dp[i][k-1] != -1) dp[i][k] = dp[dp[i][k-1]][k-1];
			else dp[i][k] = -1;
	}

	int q;
	scanf("%d", &q);

	for (int i = 0; i < q; ++i) {
		int l, r;
		scanf("%d%d", &l, &r);

		int ans = 0;
		for (int k = MAXK - 1; k >= 0; --k)
			if (dp[r][k] >= l-1) {
				r = dp[r][k];
				ans += 1 << k;
			}

		printf("%d\n", ans);
	}
}

Compilation message (stderr)

sumzero.cpp: In function 'int main()':
sumzero.cpp:14:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |  scanf("%d", &n);
      |  ~~~~~^~~~~~~~~~
sumzero.cpp:20:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |   scanf("%d", &x);
      |   ~~~~~^~~~~~~~~~
sumzero.cpp:47:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |  scanf("%d", &q);
      |  ~~~~~^~~~~~~~~~
sumzero.cpp:51:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |   scanf("%d%d", &l, &r);
      |   ~~~~~^~~~~~~~~~~~~~~~

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