bzoj3399[Usaco2009 Mar]Sand Castle城堡*

 1 #include <cstdio>
 2 #include <cstring>
 3 #include <algorithm>
 4 #define inc(i,j,k) for(int i=j;i<=k;i++)
 5 #define maxn 25010
 6 using namespace std;
 7 
 8 inline int read(){
 9     char ch=getchar(); int f=1,x=0;
10     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1; ch=getchar();}
11     while(ch>=‘0‘&&ch<=‘9‘)x=x*10+ch-‘0‘,ch=getchar();
12     return f*x;
13 }
14 int n,a[maxn],b[maxn],x,y,ans;
15 int main(){
16     n=read(); x=read(); y=read(); inc(i,1,n)a[i]=read(),b[i]=read();
17     sort(a+1,a+n+1); sort(b+1,b+n+1);
18     inc(i,1,n)if(b[i]>a[i])ans+=(b[i]-a[i])*x;else ans+=(a[i]-b[i])*y;
19     printf("%d",ans); return 0;
20 }