hdu 1164 质因子分解 （筛素数模板）+ hdu 1215

#include <iostream>#define M 100000 // [1..M]#define clr(x, k) memset((x), (k), sizeof(x))bool f[M];int d[M], p=0;void Getprime(){int i, j;p = 0;clr(f, 0);for (i=2;i<M;++i){if (!f[i]) d[p++] = i;for (j=0;(j<p && i*d[j]<M);++j){f[i*d[j]] = 1;if (i % d[j] == 0) break;}}}int main(){Getprime();int n,i,a[10000];while(scanf("%d",&n)!=EOF){int total=0;for(i=0;d[i]*d[i]<=n;i++){if(n%d[i]==0){a[total++]=d[i];n/=d[i];while(n%d[i]==0){a[total++]=d[i];n/=d[i];}}}if(n>1)a[total++]=n;printf("%d",a[0]);for(i=1;i<total;i++)printf("*%d",a[i]);printf("\n");}return 0;}

#include <iostream>using namespace std;#define M 500003      // 01会WAint main(){int i, j, t, n, k;int p[M] = {0,0};for (i=2;i<M;++i) p[i] = 1;for (i=2;i<M/2;++i)  // 枚举约数{for (j=2;j*i<M;++j){p[j*i] += i;}}scanf("%d", &n);while (n--){scanf("%d", &t);printf("%d\n", p[t]);}return 0;}

 

#include <iostream>using namespace std;#define M 500003      // 01会WAint main(){int i, j, t, n, k;int p[M] = {0,0};for (i=2;i<M;++i) p[i] = 1;for (i=2;i<M/2;++i)  // 枚举约数{for (j=2;j*i<M;++j){p[j*i] += i;}}scanf("%d", &n);while (n--){scanf("%d", &t);printf("%d\n", p[t]);}return 0;}