点击打开链接hdu4011
水贪心:
注意I64d!
#include <stdio.h>
#include <string.h>
#include <iostream>
#include <math.h>
#include <algorithm>
#include <vector>
#include <map>
#include <queue>
#include <stack>
#define PI acos(-1.0)
#define eps 1e-8
#define LL long long
#define moo 1000000007
#define INF -999999999
using namespace std;
#define maxn 101000
int main()
{int t;cin>>t;int n,b;long long sum,ans,a;int s[maxn];int Case=1;while(t--){scanf("%d%I64d%d",&n,&a,&b);sum=b+a*2;ans=a*2+b;for(int i=1;i<=n;i++)scanf("%d",s+i);for(int i=1;i<n;i++)s[i]=s[i+1]-s[i];for(int i=1;i<n;i++){if(s[i]*b>=ans)sum+=ans;else sum+=s[i]*b;}printf("Case #%d: %I64d\n",Case++,sum);}return 0;
}