FZU 1492 地震预测(链表)

实际上把数组排序一遍加入链表中，再记录好数组原来的数在链表中的位置。我们只需要维护链表的删除操作就可以了。

 

# include <cstdio>
# include <cstring>
# include <cstdlib>
# include <iostream>
# include <vector>
# include <queue>
# include <stack>
# include <map>
# include <set>
# include <cmath>
# include <algorithm>
using namespace std;
# define lowbit(x) ((x)&(-x))
# define pi 3.1415926535
# define eps 1e-9
# define MOD 1000000009
# define INF 1000000000
# define mem(a,b) memset(a,b,sizeof(a))
# define FOR(i,a,n) for(int i=a; i<=n; ++i)
# define FO(i,a,n) for(int i=a; i<n; ++i)
# define bug puts("H");
# define lch p<<1,l,mid
# define rch p<<1|1,mid+1,r
# define mp make_pair
# define pb push_back
typedef pair<int,int> PII;
typedef vector<int> VI;
# pragma comment(linker, "/STACK:1024000000,1024000000")
typedef long long LL;
int Scan() {
    int res=0, flag=0;
    char ch;
    if((ch=getchar())=='-') flag=1;
    else if(ch>='0'&&ch<='9') res=ch-'0';
    while((ch=getchar())>='0'&&ch<='9')  res=res*10+(ch-'0');
    return flag?-res:res;
}
void Out(int a) {
    if(a<0) {putchar('-'); a=-a;}
    if(a>=10) Out(a/10);
    putchar(a%10+'0');
}
const int N=100005;
//Code begin...

struct List{int cur, pre, suc;}list[N];
int a[N], b[N];

bool comp(int x, int y){return a[x]<a[y];}
int main ()
{
    int n;
    while (~scanf("%d",&n)) {
        FOR(i,1,n) scanf("%d",a+i), b[i]=i;
        a[0]=a[n+1]=INF;
        int sum=a[n];
        sort(b+1,b+n+1,comp);
        FOR(i,1,n) list[b[i]].cur=i, list[i].pre=i-1, list[i].suc=i+1;
        FO(i,1,n) {
            int j=list[i].cur;
            sum+=min(abs(a[i]-a[b[list[j].pre]]), abs(a[i]-a[b[list[j].suc]]));
            list[list[j].pre].suc=list[j].suc;
            list[list[j].suc].pre=list[j].pre;
        }
        printf("%d\n",sum);
    }
    return 0;
}