题目传送门
/*
题意:这题就是求b+1到a的因子个数和。
数学+DP:a[i]保存i的最小因子,dp[i] = dp[i/a[i]] +1;再来一个前缀和
*/
/************************************************
Author :Running_Time
Created Time :2015-8-1 14:08:34
File Name :B.cpp
*************************************************/
#include <cstdio>
#include <algorithm>
#include <iostream>
#include <sstream>
#include <cstring>
#include <cmath>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <list>
#include <map>
#include <set>
#include <bitset>
#include <cstdlib>
#include <ctime>
using namespace std;
typedef long long ll;
const int MAXN = 5e6 + ;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + ;
int cnt[MAXN];
int a[MAXN];
bool is_prime[MAXN];
int prime[MAXN/];
ll dp[MAXN];
ll sum[MAXN];
void solve(void) {
memset (is_prime, true, sizeof (is_prime));
for (int i=; i<=; ++i) a[i] = i;
int tot = ;
for (int i=; i<=; ++i) {
if (is_prime[i]) prime[++tot] = i;
for (int j=; j<=tot && i*prime[j]<=; ++j) {
int tmp = i * prime[j];
is_prime[tmp] = false;
if (a[tmp] > prime[j]) a[tmp] = prime[j];
if (i % prime[j] == ) break;
}
}
dp[] = ;
for (int i=; i<=; ++i) {
dp[i] = dp[i/a[i]] + ;
}
for (int i=; i<=; ++i) {
sum[i] = sum[i-] + dp[i];
}
}
int main(void) { //Codeforces Round #304 (Div. 2) D. Soldier and Number Game
solve ();
int T; scanf ("%d", &T);
while (T--) {
int l, r; scanf ("%d%d", &r, &l);
if (l == r) {
puts (""); continue;
}
printf ("%I64d\n", sum[r] - sum[l]);
}
return ;
}