1 #include <cstdio> 2  3 using namespace std; 4  5 #define NN    100010 6 int g[NN], f[NN]; 7  8 int main(void) 9 {10     int N;11     while(scanf("%d", &N) > 0) {12         for(int i=1; i<=N; ++i) scanf("%d", &f[i]);13         for(int i=1; i<=N; ++i) g[i] = 0;14         for(int i=1; i<=N; ++i) {15             if (!g[i]) {16                 putchar(‘(‘);17                 int t = i;18                 do {19                     printf(t != i? " %d" : "%d", t);20                     g[t] = 1;21                     t = f[t];22                 } while(t != i);23                 putchar(‘)‘);24             }25         }26         putchar(‘\n‘);27     }28     return 0;29 }

 1 #include <cstdio> 2 #include <cmath> 3 using namespace std; 4  5 #define NN    110000 6 double g[NN + 1]; 7  8 int main(void) 9 {10     for(int i=1; i<=NN; ++i) g[i] = g[i-1] + 1/(double)i;11     int N;12     while(scanf("%d", &N) > 0)13         printf("%.4f\n", N<=NN ? g[N] : log(N+1) + 0.577215664);14     return 0;15 }