【HDOJ】1695 GCD

莫比乌斯反演简单题目。

 /* 1695 */
 #include <iostream>
 #include <string>
 #include <map>
 #include <queue>
 #include <set>
 #include <stack>
 #include <vector>
 #include <deque>
 #include <algorithm>
 #include <cstdio>
 #include <cmath>
 #include <ctime>
 #include <cstring>
 #include <climits>
 #include <cctype>
 #include <cassert>
 #include <functional>
 using namespace std;
 //#pragma comment(linker,"/STACK:102400000,1024000")

 #define mpii            map<int,int>
 #define vi                vector<int>
 #define pii                pair<int,int>
 #define rep(i, a, n)     for (int i=a;i<n;++i)
 #define per(i, a, n)     for (int i=n-1;i>=a;--i)
 #define pb                 push_back
 #define mp                 make_pair
 #define all(x)             (x).begin(),(x).end()
 #define SZ(x)             ((int)(x).size())
 #define lson            l, mid, rt<<1
 #define rson            mid+1, r, rt<<1|1

 const int maxn = ;
 int P[maxn];
 bool visit[maxn];
 int mu[maxn], m = ;

 void init() {
     int i, j, k;

     memset(visit, false, sizeof(visit));
     mu[] = ;
     for (i=; i<maxn; ++i) {
         if (!visit[i]) {
             P[m++] = i;
             mu[i] = -;
         }
         for (j=; j<m; ++j) {
             k = P[j] * i;
             if (k > maxn)
                 break;
             visit[k] = true;
             if (i%P[j] == ) {
                 mu[k] = ;
                 break;
             } else {
                 mu[k] = -mu[i];
             }
         }
     }
 }

 int main() {

     #ifndef ONLINE_JUDGE
         freopen("data.in", "r", stdin);
         freopen("data.out", "w", stdout);
     #endif

     int a, b, c, d, k;
     int tt;
     __int64 ans, tmp;

     init();
     scanf("%d", &tt);
     rep(t, , tt+) {
         scanf("%d %d %d %d %d",&a,&b,&c,&d,&k);
         if (k == ) {
             ans = ;
         } else {
             b /= k;
             d /= k;
             if (b > d)
                 swap(b, d);
             ans = tmp = ;
             rep(i, , b+)
                 ans += 1LL * mu[i] * (b/i) * (d/i);
             rep(i, , b+)
                 tmp += 1LL * mu[i] * (b/i) * (b/i);
             #ifndef ONLINE_JUDGE
                 printf("%I64d %I64d\n", ans, tmp);
             #endif
             ans -= tmp/;
         }
         printf("Case %d: %I64d\n", t, ans);
     }

     #ifndef ONLINE_JUDGE
         printf("time = %d\n", (int)(clock()));
     #endif

     return ;
 }