Submission #16714

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
16714	2015-09-08T09:11:07 Z	gs14004	Xtreme gcd sum (kriii2_X)	C++14	1 / 4	4000 ms	44688 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;

lint mod_inv(int x, int p){
	lint ret = 1, piv = x;
	while(p){
		if(p&1) ret *= piv;
		piv *= piv;
		ret %= mod;
		piv %= mod;
		p >>= 1;
	}
	return ret;
}

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;
	}
}

vector<int> change[1000005];
int dx[1000005];
lint cnt[1000005];

int main(){
	scanf("%d",&n);
	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] *= mod_inv(cur, mod - 2);
				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	215 ms	44688 KB	Output is correct
2	Correct	210 ms	44688 KB	Output is correct
3	Correct	212 ms	44688 KB	Output is correct
4	Correct	212 ms	44688 KB	Output is correct
5	Correct	214 ms	44688 KB	Output is correct
6	Correct	205 ms	44688 KB	Output is correct
7	Correct	207 ms	44688 KB	Output is correct
8	Correct	208 ms	44688 KB	Output is correct
9	Correct	208 ms	44688 KB	Output is correct
10	Correct	209 ms	44688 KB	Output is correct
11	Correct	212 ms	44688 KB	Output is correct
12	Correct	210 ms	44688 KB	Output is correct
13	Correct	216 ms	44688 KB	Output is correct
14	Correct	216 ms	44688 KB	Output is correct
15	Correct	209 ms	44688 KB	Output is correct
16	Correct	216 ms	44688 KB	Output is correct
17	Correct	213 ms	44688 KB	Output is correct
18	Correct	215 ms	44688 KB	Output is correct
19	Correct	209 ms	44688 KB	Output is correct
20	Correct	222 ms	44688 KB	Output is correct
21	Correct	212 ms	44688 KB	Output is correct
22	Correct	214 ms	44688 KB	Output is correct
23	Correct	219 ms	44688 KB	Output is correct
24	Correct	216 ms	44688 KB	Output is correct
25	Correct	214 ms	44688 KB	Output is correct

Subtask #2

0.0 / 3.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	210 ms	44688 KB	Output is correct
2	Correct	206 ms	44688 KB	Output is correct
3	Correct	217 ms	44688 KB	Output is correct
4	Correct	206 ms	44688 KB	Output is correct
5	Correct	206 ms	44688 KB	Output is correct
6	Correct	204 ms	44688 KB	Output is correct
7	Correct	213 ms	44688 KB	Output is correct
8	Correct	210 ms	44688 KB	Output is correct
9	Correct	216 ms	44688 KB	Output is correct
10	Correct	215 ms	44688 KB	Output is correct
11	Correct	755 ms	44688 KB	Output is correct
12	Correct	758 ms	44688 KB	Output is correct
13	Correct	764 ms	44688 KB	Output is correct
14	Correct	755 ms	44688 KB	Output is correct
15	Correct	759 ms	44688 KB	Output is correct
16	Correct	238 ms	44688 KB	Output is correct
17	Correct	248 ms	44688 KB	Output is correct
18	Correct	2608 ms	44688 KB	Output is correct
19	Correct	3269 ms	44688 KB	Output is correct
20	Correct	2372 ms	44688 KB	Output is correct
21	Correct	1307 ms	44688 KB	Output is correct
22	Execution timed out	4000 ms	44684 KB	Program timed out
23	Halted	0 ms	0 KB	-