Submission #610893

#	Time	Username	Problem	Language	Result	Execution time	Memory
610893		racsosabe	Poklon (COCI17_poklon)	C++14	140 / 140	750 ms	32372 KiB

poklon

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

const int N = 500000 + 5;

int n;
int q;
int a[N];
int L[N];
int st[N << 2];
int ans[N];
int last1[N];
int last2[N];
int last3[N];
vector<int> Q[N];

void compress(){
	set<int> S;
	for(int i = 1; i <= n; i++) S.emplace(a[i]);
	int len = 0;
	map<int, int> id;
	for(int x : S){
		id[x] = len++;
	}
	for(int i = 1; i <= n; i++) a[i] = id[a[i]];
}

void update(int x, int y, int pos = 1, int l = 1, int r = n + 1){
	if(l == r){
		st[pos] += y;
		return;
	}
	int mi = (l + r) / 2;
	if(x <= mi) update(x, y, 2 * pos, l, mi);
	else update(x, y, 2 * pos + 1, mi + 1, r);
	st[pos] = st[2 * pos] + st[2 * pos + 1];
}

int query(int x, int y, int pos = 1, int l = 1, int r = n + 1){
	if(y < l or r < x) return 0;
	if(x <= l and r <= y) return st[pos];
	int mi = (l + r) / 2;
	return query(x, y, 2 * pos, l, mi) + query(x, y, 2 * pos + 1, mi + 1, r);
}

int get_sum(int pos){
	return query(1, pos);
}

void fix(int i){
	int x = a[i];
	int l1 = last1[x], l2 = last2[x], l3 = last3[x];
	if(l2){
		update(l3 + 1, -1);
		update(l2 + 1, 1);
	}
	if(l1){
		update(l2 + 1, 1);
		update(l1 + 1, -1);
	}
	last3[x] = l2;
	last2[x] = l1;
	last1[x] = i;
}

void download(int i){
	for(int at : Q[i]){
		ans[at] = get_sum(L[at]);
	}
}

void solve(){
	for(int i = 1; i <= n; i++){
		fix(i);
		download(i);
	}
}

int main(){
	scanf("%d %d", &n, &q);
	for(int i = 1; i <= n; i++) scanf("%d", a + i);
	compress();
	for(int i = 1; i <= q; i++){
		int r;
		scanf("%d %d", L + i, &r);
		Q[r].emplace_back(i);
	}
	solve();
	for(int i = 1; i <= q; i++) printf("%d\n", ans[i]);
	return 0;
}

Compilation message (stderr)

poklon.cpp: In function 'int main()':
poklon.cpp:80:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   80 |  scanf("%d %d", &n, &q);
      |  ~~~~~^~~~~~~~~~~~~~~~~
poklon.cpp:81:35: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |  for(int i = 1; i <= n; i++) scanf("%d", a + i);
      |                              ~~~~~^~~~~~~~~~~~~
poklon.cpp:85:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   85 |   scanf("%d %d", L + i, &r);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~

• Subtask 1: 140 / 140