HDU5317 (more than 2015 schools 3)--RGCDQ (prime Sieve + enumeration)

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Definition f (i) for the type of prime number comprising I, the maximum value of gcd (f (i), F (j)) (L <= i < J <= R) within the interval [l,r]

The prime number sieve 10^6 in the prime, the F (i) of each count, can be found F (i) <= 7, with an array of statistics S[I][J] from 2 to I f (x) =j how many, subtract directly from the calculation interval and judge the maximum GCD

#include <cstdio> #include <cstring> #include <cmath> #include <algorithm>using namespace std;  Define LL __int64#define maxn 1000000+10int A[MAXN], CHECK[MAXN]; int tot; int NUM[MAXN]; int s[maxn][10]; void Get_pri ()    {int I, J;    tot = 0;    memset (check,0,sizeof (check));        for (i = 2; I <= 1000000; i++) {if (!check[i]) a[tot++] = i;            for (j = 0; J < tot; J + +) {if (I*a[j] >= 1000000) break;            check[I*a[j]] = 1;        if (i%a[j] = = 0) break;    }}}int f (int x) {int J, cnt = 0;        for (j = 0; a[j]*a[j] <= x; j + +) {if (x%a[j] = = 0) cnt++;        while (x%a[j] = = 0) x/= a[j];    if (x = = 1) break;    } if (x! = 1) cnt++; return CNT;}    int main () {int T, L, R;    int I, j, ans;    Get_pri ();    for (i = 2; I <= 1000000; i++) num[i] = f (i);    Memset (s,0,sizeof (s)); for (i = 2; I <= 1000000; i++) {for (j = 1; J <= 7;        J + +) S[i][j] = S[i-1][j];    s[i][Num[i]]++;    } scanf ("%d", &t);        while (t--) {scanf ("%d%d", &l, &r);        ans = 1;            for (i = 1; I <= 7; i++) {s[0][i] = S[r][i]-s[l-1][i];        if (S[0][i] > 1) ans = i;        } if (s[0][3]+s[0][6] = = 2) ans = max (ans,3);        if (S[0][2]+s[0][4]+s[0][6] >= 2) ans = max (ans,2);    printf ("%d\n", ans); } return 0;}

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HDU5317 (more than 2015 schools 3)--RGCDQ (prime Sieve + enumeration)