Cod sursa(job #1324530)

Utilizator BonCipBonciocat Ciprian Mircea BonCip Data 22 ianuarie 2015 15:15:56
Problema Fractii Scor 30
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.1 kb
#include <stdio.h>
#define NMAX 1000000

int minp[NMAX + 1], phi[NMAX + 1];

void preproc()
{
    /// minp
    minp[1] = 1;
    int i, j;
    for (i = 2; i <= NMAX; i++) {
        if (minp[i] == 0) {
            for (j = i; j <= NMAX; j += i) {
                if (minp[j] == 0) {
                    minp[j] = i;
                }
            }
        }
    }

    /// phi
    phi[1] = 1;
    for (i = 2; i <= NMAX; i++) {
        if (i % (minp[i] * minp[i]) == 0) {
            phi[i] = phi[i / minp[i]] * minp[i];
        } else {
            phi[i] = phi[i / minp[i]] * (minp[i] - 1);
        }
        if (i <= 20) {
            printf("%d %d\n", i, phi[i]);
        }
    }
}

int main()
{
    FILE *fin, *fout;
    fin = fopen("fractii.in", "r");
    fout = fopen("fractii.out", "w");

    preproc();

    int N;
    fscanf(fin, "%d", &N);

    long long cnt = 0;
    int i;
    for (i = 1; i <= N; i++) {
        cnt += phi[i];
        printf("%d ", phi[i]);
    }
    fprintf(fout, "%I64d\n", 2 * cnt - 1);


    fclose(fin);
    fclose(fout);
    return 0;
}