曼哈顿树
#include <bits/stdc++.h> #define inf 2333333333333333 #define N 1000010 #define p(a) putchar(a) #define For(i,a,b) for(long long i=a;i<=b;++i) using namespace std; long long n,ans,mod=1e9+7; long long a[N]; struct node{ long long data; node *l; node *r; }*rt; struct node_comparison { bool operator () ( const node* a, const node* b ) const { return a->data > b->data; } }; priority_queue<node*,vector<node*>,node_comparison>q; void in(long long &x){ long long y=1;char c=getchar();x=0; while(c<'0'||c>'9'){if(c=='-')y=-1;c=getchar();} while(c<='9'&&c>='0'){ x=(x<<1)+(x<<3)+c-'0';c=getchar();} x*=y; } void o(long long x){ if(x<0){p('-');x=-x;} if(x>9)o(x/10); p(x%10+'0'); } void build(){ while(!q.empty()){ auto temp=(node*)malloc(sizeof(node)); auto temp1=q.top();q.pop(); auto temp2=q.top();q.pop(); temp->data=temp1->data+temp2->data; temp->l=temp1; temp->r=temp2; if(q.empty()){ rt=temp; break; } q.push(temp); } } void dfs(node* now,long long deep){ if(now==NULL) return; if(now->l==NULL && now->r==NULL){ ans+=deep*now->data; ans%=mod; return; } dfs(now->l,deep+1); dfs(now->r,deep+1); } signed main(){ while(cin>>n){ For(i,1,n) in(a[i]); rt=(node*)malloc(sizeof(node)); ans=0; For(i,1,n){ auto temp=(node*)malloc(sizeof(node)); temp->data=a[i]; temp->l=NULL; temp->r=NULL; q.push(temp); } build(); dfs(rt,0); o(ans);p('\n'); } return 0; }