Submission #365489

#	Time	Username	Problem	Language	Result	Execution time	Memory
365489		tfg	popa (BOI18_popa)	C++17	Compilation error	0 ms	0 KiB

popa

#include <iostream>
#include <vector>
#include <chrono>
#include <random>
#include <cassert>
#include "popa.h"
#include <stack>

std::mt19937 rng((int) std::chrono::steady_clock::now().time_since_epoch().count());

// query(a, b, c, d) gcd[a, b] == gcd[c, d]

const int ms = 1010;

int liml[ms], limr[ms];

int solve(int l, int r, int* Left, int* Right) {
	if(l >= r) {
		return -1;
	}
	for(int i = l; i < r; i++) {
		if(liml[i] <= l && r <= limr[i]) {
			Left[i] = solve(l, i, Left, Right);
			Right[i] = solve(i+1, r, Left, Right);
			return i;
		}
	}
	assert(0);
}

int solve(int n, int *l, int *r) {
	for(int i = 0; i < n; i++) {
		l[i] = r[i] = -1;
	}
	std::vector<int> st;
	for(int i = 0; i < n; i++) {
		while(!st.empty() && query(st.back(), st.back(), st.back(), i) != 0) {
			// [st.back(), i] isn't good for st.back
			limr[st.back()] = i;
			st.pop_back();
		}
		liml[i] = st.empty() ? 0 : st.back() + 1;
	}
	assert(!st.empty());
	for(auto val : st) {
		limr[i] = n;
	}
	solve(0, n, l, r);
}

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

Compilation message (stderr)

popa.cpp: In function 'int solve(int, int*, int*)':
popa.cpp:46:8: error: 'i' was not declared in this scope
   46 |   limr[i] = n;
      |        ^
popa.cpp:45:11: warning: unused variable 'val' [-Wunused-variable]
   45 |  for(auto val : st) {
      |           ^~~
popa.cpp:35:19: warning: control reaches end of non-void function [-Wreturn-type]
   35 |  std::vector<int> st;
      |                   ^~