oj.uz

답안 #16716

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
16716 2015-09-08T09:39:00 Z gs14004 Xtreme gcd sum (kriii2_X) C++14
4 / 4
 1137 ms 29064 KB 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <limits.h>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <algorithm>
#include <string>
#include <functional>
#include <vector>
#include <numeric>
#include <deque>
#include <utility>
#include <bitset>
#include <iostream>
using namespace std;
typedef long long lint;
typedef long double llf;
typedef pair<int, int> pi;

const int mod = 1e9 + 7;
const int maxp = 1e6;

int che[1000005];
int moebius[1000005];
int n;

void get_moebius(){
	for(int i=2; i<=maxp; i++){
		for(int j=i; j<=maxp; j+=i){
			if(!che[j]) che[j] = i;
		}
	}
	for(int i=1; i<=maxp; i++){
		int cnt = 0, lst = -1;
		int x = i;
		while(x > 1){
			if(lst == che[x]){
				cnt = -1;
				break;
			}
			lst = che[x];
			x /= lst;
			cnt++;
		}
		if(cnt < 0) continue;
		moebius[i] = cnt % 2 ? -1 : 1;
	}
}

int dx[1000005];
lint cnt[1000005];
lint inv[1000005];

int main(){
	scanf("%d",&n);
	for(int i=1; i<=maxp; i++){
		lint ret = 1, piv = i;
		int p = mod - 2;
		while(p){
			if(p&1) ret *= piv;
			piv *= piv;
			ret %= mod;
			piv %= mod;
			p >>= 1;
		}
		inv[i] = ret;
	}
	fill(cnt, cnt + maxp + 1, 1);
	for(int i=0; i<n; i++){
		int a, b;
		scanf("%d %d",&a, &b);
		int pos = 1, cur = -1;
		int nxt_update = 1;
		while(pos <= maxp){
			cur = b / pos - (a - 1) / pos;
			nxt_update = 1e9;
			int T = b / pos - 1;
			if(T >= 0){
				int s = (b + T + 1) / (T + 1);
				if(s > pos) nxt_update = min(nxt_update, s);
			}
			T = (a - 1) / pos - 1;
			if(T >= 0){
				int s = (a + T) / (T + 1);
				if(s > pos) nxt_update = min(nxt_update, s);
			}
			nxt_update = min(nxt_update, maxp + 1);
			if(cur == 0){
				dx[pos]++;
				dx[nxt_update]--;
			}
			else{
				cnt[nxt_update] *= inv[cur];
				cnt[pos] *= cur;
				cnt[pos] %= mod;
				cnt[nxt_update] %= mod;
			}
			pos = nxt_update;
		}
	}
	for(int i=1; i<=maxp; i++){
		cnt[i] *= cnt[i-1];
		dx[i] += dx[i-1];
		cnt[i] %= mod;
	}
	for(int i=1; i<=maxp; i++){
		if(dx[i]) cnt[i] = 0;
	}
	get_moebius();
	lint ret = 0;
	for(int i=1; i<=maxp; i++){
		for(int j=1; i*j<=maxp; j++){
			ret += 1ll * i * moebius[j] * cnt[i * j] % mod;
			ret %= mod;
		}
	}
	ret += mod;
	ret %= mod;
	printf("%lld",ret);
}

Subtask #1
1.0 / 1.0

# 결과 실행 시간 메모리 Grader output
1 Correct 460 ms 29064 KB Output is correct
2 Correct 452 ms 29064 KB Output is correct
3 Correct 459 ms 29064 KB Output is correct
4 Correct 478 ms 29064 KB Output is correct
5 Correct 457 ms 29064 KB Output is correct
6 Correct 430 ms 29064 KB Output is correct
7 Correct 454 ms 29064 KB Output is correct
8 Correct 457 ms 29064 KB Output is correct
9 Correct 456 ms 29064 KB Output is correct
10 Correct 455 ms 29064 KB Output is correct
11 Correct 451 ms 29064 KB Output is correct
12 Correct 461 ms 29064 KB Output is correct
13 Correct 446 ms 29064 KB Output is correct
14 Correct 460 ms 29064 KB Output is correct
15 Correct 455 ms 29064 KB Output is correct
16 Correct 451 ms 29064 KB Output is correct
17 Correct 455 ms 29064 KB Output is correct
18 Correct 454 ms 29064 KB Output is correct
19 Correct 456 ms 29064 KB Output is correct
20 Correct 453 ms 29064 KB Output is correct
21 Correct 457 ms 29064 KB Output is correct
22 Correct 458 ms 29064 KB Output is correct
23 Correct 445 ms 29064 KB Output is correct
24 Correct 461 ms 29064 KB Output is correct
25 Correct 451 ms 29064 KB Output is correct

Subtask #2
3.0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 450 ms 29064 KB Output is correct
2 Correct 453 ms 29064 KB Output is correct
3 Correct 451 ms 29064 KB Output is correct
4 Correct 454 ms 29064 KB Output is correct
5 Correct 461 ms 29064 KB Output is correct
6 Correct 456 ms 29064 KB Output is correct
7 Correct 450 ms 29064 KB Output is correct
8 Correct 451 ms 29064 KB Output is correct
9 Correct 451 ms 29064 KB Output is correct
10 Correct 454 ms 29064 KB Output is correct
11 Correct 537 ms 29064 KB Output is correct
12 Correct 521 ms 29064 KB Output is correct
13 Correct 525 ms 29064 KB Output is correct
14 Correct 521 ms 29064 KB Output is correct
15 Correct 527 ms 29064 KB Output is correct
16 Correct 459 ms 29064 KB Output is correct
17 Correct 458 ms 29064 KB Output is correct
18 Correct 757 ms 29064 KB Output is correct
19 Correct 834 ms 29064 KB Output is correct
20 Correct 683 ms 29064 KB Output is correct
21 Correct 594 ms 29064 KB Output is correct
22 Correct 1044 ms 29064 KB Output is correct
23 Correct 1137 ms 29064 KB Output is correct
24 Correct 946 ms 29064 KB Output is correct
25 Correct 949 ms 29064 KB Output is correct