D. Arpa and a list of numbers Codeforces Round #432 (Div. 2, based on IndiaHacks Final Round 2017)
http://codeforces.com/contest/851/problem/D
分区间操作
1 #include <cstdio> 2 #include <cstdlib> 3 #include <cmath> 4 #include <cstring> 5 #include <time.h> 6 #include <string> 7 #include <set> 8 #include <map> 9 #include <list> 10 #include <stack> 11 #include <queue> 12 #include <vector> 13 #include <bitset> 14 #include <ext/rope> 15 #include <algorithm> 16 #include <iostream> 17 using namespace std; 18 #define ll long long 19 #define minv 1e-6 20 #define inf 1e18 21 #define pi 3.1415926536 22 #define E 2.7182818284 23 const ll mod=1e9+7;//998244353 24 const int maxn=2e6+10; 25 26 bool vis[maxn]={0}; 27 ll tot[maxn]={0},sum[maxn]={0}; 28 29 int main() 30 { 31 int n,x,y,z,i,j,pos; 32 ll v,r=inf,a; 33 scanf("%d%d%d",&n,&x,&y); 34 z=x/y; 35 for (i=1;i<=n;i++) 36 { 37 scanf("%lld",&a); 38 tot[a]++; 39 sum[a]+=a; 40 } 41 for (i=1;i<=2e6;i++) 42 tot[i]+=tot[i-1],sum[i]+=sum[i-1]; 43 for (i=2;i<=1e6;i++) 44 if (!vis[i]) 45 { 46 v=0; 47 //(j-i,j) 48 for (j=i;j<=2e6;j+=i) 49 { 50 pos=max(j-z,j-i+1);//[pos,j] 51 v+= (ll)(tot[pos-1]-tot[j-i])*x + ( (ll)(tot[j]-tot[pos-1])*j-(ll)(sum[j]-sum[pos-1]) )*y; 52 vis[j]=1; 53 } 54 r=min(r,v); 55 } 56 cout<<r; 57 return 0; 58 }
