HNU 12876 Quite Good Numbers 完美数变形

筛法是一种很快的方法，贴代码纪念一下。 做法很像筛法

 #include <iostream>
 #include <cstdio>
 #include <cstring>
 #include <cstdlib>
 #include <cmath>
 #include <algorithm>
 #include <string>
 #include <queue>
 #include <stack>
 #include <vector>
 #include <map>
 #include <set>
 #include <functional>
 #include <time.h>

 using namespace std;

 const int INF = <<;
 const int MAXN = (int) 1e6+;

 int a[MAXN];

 inline int myAbs(int x) {
     return x> ? x : -x;
 }

 int main() {
     #ifdef Phantom01
         freopen("HNU12876.in", "r", stdin);
     #endif //Phantom01

     memset(a, , sizeof(a));
     for (int i = ; i < MAXN; i++)
         for (int j = i<<; j < MAXN; j += i)
             a[j]+=i;
     for (int i = ; i < MAXN; i++)
         a[i] = myAbs(a[i]-i);

     int l, r, k;
     int T = ;
     while (scanf("%d%d%d", &l, &r, &k)!=EOF) {
         if (l==r&&r==k&&k==) break;
         printf("Test %d: ", T++);
         int ans = ;
         for (int i = l; i <= r; i++)
             if (a[i]<=k)
                 ans++;
         printf("%d\n", ans);
     }

     return ;
 }