Submission #943499

#	Time	Username	Problem	Language	Result	Execution time	Memory
943499		KickingKun	Sum Zero (RMI20_sumzero)	C++14	100 / 100	324 ms	19068 KiB

sumzero

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

#define ll long long
#define ull unsigned long long
#define ld long double
#define bigint __int128
#define emb emplace_back
#define pb push_back
#define pii pair <int, int>
#define fi first
#define se second
#define all(v) v.begin(), v.end()
#define Task ""

#define MASK(k) (1ull << k)
#define bitcnt(k) __builtin_popcount(k)
#define testBit(n, k) ((n >> k) & 1)
#define flipBit(n, k) (n ^ (1ll << k))
#define offBit(n, k) (n & ~MASK(k))
#define onBit(n, k) (n | (1ll << k))

template <class T> bool minimize(T &a, T b) {if (a > b) {a = b; return true;} return false;}
template <class T> bool maximize(T &a, T b) {if (a < b) {a = b; return true;} return false;}

const int N = 4e5 + 5, LG = 5, mod = 1e9 + 7;
const ll INF = 1e18;

int n, up[N][LG];
unordered_map <ll, int> pos;

int main() {
	ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);

	if (fopen(Task".inp", "r")) {
		freopen(Task".inp", "r", stdin);
		freopen(Task".out", "w", stdout);
	}
	
	cin >> n;
	for (int j = 0; j < LG; j++)
		for (int i = 0; i <= n; i++)
			up[i][j] = n + 1;
	
	pos[0] = 0; ll sum = 0;
	for (int i = 1; i <= n; i++) {
		int x; cin >> x; sum += x;
		if (pos.count(sum)) up[pos[sum]][0] = i;
		pos[sum] = i;
	}
	for (int i = n - 1; i >= 0; i--) minimize(up[i][0], up[i + 1][0]);
	
	for (int j = 1; j < LG; j++)
		for (int i = 0; i <= n; i++) {
			int pos = i;
			for (int times = 0; times < 16; times++)
				if (pos <= n) pos = up[pos][j - 1];
			up[i][j] = pos;
		}
	
	int q; cin >> q;
	while (q--) {
		int l, r; cin >> l >> r;
		int pos = l - 1, ans = 0, k = LG - 1;
		while (k >= 0) {
			if (up[pos][k] <= r) pos = up[pos][k], ans += (1 << (4 * k));
			else --k;
		}
		cout << ans << '\n';
	}
}

Compilation message (stderr)

sumzero.cpp: In function 'int main()':
sumzero.cpp:37:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |   freopen(Task".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
sumzero.cpp:38:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |   freopen(Task".out", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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