Submission #16716

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
16716	2015-09-08T09:39:00 Z	gs14004	Xtreme gcd sum (kriii2_X)	C++14	4 / 4	1137 ms	29064 KB

X

#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

#	Verdict	Execution time	Memory	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

#	Verdict	Execution time	Memory	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