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https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
43 lines
1.0 KiB
C++
43 lines
1.0 KiB
C++
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#include <iostream>
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#include <cstdio>
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#include <cstring>
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#include <algorithm>
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#include <bitset>
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using namespace std;
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const int maxn = 1005;
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bitset<maxn> a[maxn];
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int main() {
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int t, cas = 1;
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int n;
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scanf("%d", &t);
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while (t--) {
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scanf("%d", &n);
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for (int i = 0; i < n; i++) {
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a[i].reset();
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a[i][i] = 1;
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}
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int c, x;
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for (int i = 0; i < n; i++) {
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scanf("%d", &c);
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while (c--) {
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scanf("%d", &x);
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a[i][--x] = 1;
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}
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}
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for (int i = 0; i < n; i++)
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for (int j = 0; j < n; j++)
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if (a[j][i])
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a[j] |= a[i];
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double ans = 0;
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for (int i = 0; i < n; i++) {
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c = 0;
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for (int j = 0; j < n; j++)
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if (a[j][i])
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c++;
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ans += 1.0 / c;
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}
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printf("Case #%d: %.5lf\n",cas++,ans);
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}
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return 0;
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}
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