Friends number

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Paula and Tai are couple. There are many stories between them. The day Paula left by airplane, Tai send one message to telephone 2200284, then, everything is changing… (The story in “the snow queen”).

After a long time, Tai tells Paula, the number 220 and 284 is a couple of friends number, as they are special, all divisors of 220’s sum is 284, and all divisors of 284’s sum is 220. Can you find out there are how many couples of friends number less than 10,000. Then, how about 100,000, 200,000 and so on.

The task for you is to find out there are how many couples of friends number in given closed interval [a,b]。

Input

There are several cases.
Each test case contains two positive integers a, b(1<= a <= b <=5,000,000).
Proceed to the end of file.

Output

For each test case, output the number of couples in the given range. The output of one test case occupied exactly one line.

Sample Input

1 1001 1000

Sample Output

Hint

6 is a number whose sum of all divisors is 6. 6 is not a friend number, these number is called Perfect Number.

题意：让找出友元数，即一个数的饿因子和等于另一个数的值，另一个的因子和等于这个值，让你找出a~b范围内的这样的友元数有几对

思路：打表

#include<iostream>#include<string>#include<cstdio>#include<algorithm>#include<cmath>#include<cstring>#include<set>using namespace std;#define INF 1.0e14;typedef long long LL;int main(){    int b[150]= {220, 284,  1184, 1210,  2620, 2924,  5020, 5564,                 6232, 6368,  10744, 10856,  12285, 14595,  17296, 18416,                 63020, 76084,  66928, 66992,  67095, 71145,  69615, 87633,                 79750, 88730,  100485, 124155,  122265, 139815,  122368, 123152,                 141664, 153176,  142310, 168730,  171856, 176336,  176272, 180848,                 185368, 203432,  196724, 202444,  280540, 365084,  308620, 389924,                 319550, 430402,  356408, 399592,  437456, 455344,  469028, 486178,                 503056, 514736,  522405, 525915,  600392, 669688,  609928, 686072,                 624184, 691256,  635624, 712216,  643336, 652664,  667964, 783556,                 726104, 796696,  802725, 863835,  879712, 901424,  898216, 980984,                 947835, 1125765,  998104, 1043096,  1077890, 1099390,  1154450, 1189150,                 1156870, 1292570,  1175265, 1438983,  1185376, 1286744,  1280565, 1340235,                 1328470, 1483850,  1358595, 1486845,  1392368, 1464592,  1466150, 1747930,                 1468324, 1749212,  1511930, 1598470,  1669910, 2062570,  1798875, 1870245,                 2082464, 2090656,  2236570, 2429030,  2652728, 2941672,  2723792, 2874064,                 2728726, 3077354,  2739704, 2928136,  2802416, 2947216,  2803580, 3716164,                 3276856, 3721544,  3606850, 3892670,  3786904, 4300136,  3805264, 4006736,                 4238984, 4314616,  4246130, 4488910,  4259750, 4445050                };    int x,y;    while(cin>>x>>y)    {        int sum=0;        for(int i=0; i<=145; i+=2)        {            if(b[i]>=x&&y>=b[i+1])                sum++;        }        cout<<sum<<endl;    }}

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