n天
n个营业额;
sum(min(abs(wi-前面)));
splay维护一下就可以
1 #include<stdio.h> 2 #include<algorithm> 3 #include<math.h> 4 5 using namespace std; 6 #define inf 2000000000 7 int sum,time,flag,root; 8 9 struct node 10 { 11 int fa,l,r,w; 12 }tree[100010]; 13 void rightrotate(int x) //右旋 14 { 15 int y=tree[x].fa; 16 int z=tree[y].fa; 17 tree[y].l=tree[x].r; 18 if(tree[x].r!=-1) 19 tree[tree[x].r].fa=y; 20 tree[x].fa=z; 21 if(z!=-1) 22 { 23 if(tree[z].l==y) 24 tree[z].l=x; 25 else 26 tree[z].r=x; 27 } 28 tree[x].r=y; 29 tree[y].fa=x; 30 } 31 void leftrotate(int x)//左旋 32 { 33 int y=tree[x].fa; 34 int z=tree[y].fa; 35 tree[y].r=tree[x].l; 36 if(tree[x].l!=-1) 37 tree[tree[x].l].fa=y; 38 tree[x].fa=z; 39 if(z!=-1) 40 { 41 if(tree[z].l==y) 42 tree[z].l=x; 43 else 44 tree[z].r=x; 45 } 46 tree[x].l=y; 47 tree[y].fa=x; 48 } 49 void splay(int x) 50 { 51 while(tree[x].fa!=-1) 52 { 53 int y=tree[x].fa; 54 int z=tree[y].fa; 55 if(z==-1) //6种旋转情况 56 { 57 if(tree[y].l==x) 58 rightrotate(x); 59 else 60 leftrotate(x); 61 } 62 else 63 { 64 if(tree[z].l==y&&tree[y].l==x) 65 { 66 rightrotate(y); 67 rightrotate(x); 68 } 69 else if(tree[z].l==y&&tree[y].r==x) 70 { 71 leftrotate(x); 72 rightrotate(x); 73 } 74 else if(tree[z].r==y&&tree[y].r==x) 75 { 76 leftrotate(y); 77 leftrotate(x); 78 } 79 else 80 { 81 rightrotate(x); 82 leftrotate(x); 83 } 84 } 85 } 86 root=x; 87 } 88 void BST_insert(int w,int x) //插入 就和二叉排序树一样 89 { 90 if(w==tree[x].w) 91 { 92 flag=false; 93 splay(x); 94 return ; 95 } 96 else if(w<tree[x].w) 97 { 98 if(tree[x].l==-1) 99 { 100 tree[x].l=time; 101 tree[time].fa=x; 102 tree[time].l=tree[time].r=-1; 103 tree[time].w=w; 104 } 105 else 106 BST_insert(w,tree[x].l); 107 } 108 else 109 { 110 if(tree[x].r==-1) 111 { 112 tree[x].r=time; 113 tree[time].fa=x; 114 tree[time].l=tree[time].r=-1; 115 tree[time].w=w; 116 } 117 else 118 BST_insert(w,tree[x].r); 119 } 120 } 121 int f_pr(int x) //前面最大 122 { 123 int y=tree[x].l; 124 if(y==-1) 125 return y; 126 while(tree[y].r!=-1) 127 y=tree[y].r; 128 return y; 129 } 130 int f_ne(int x) //后面最小 131 { 132 int y=tree[x].r; 133 if(y==-1) 134 return y; 135 while(tree[y].l!=-1) 136 y=tree[y].l; 137 return y; 138 } 139 void Insert(int w) 140 { 141 flag=true; 142 time++; 143 BST_insert(w,root); 144 if(flag==false) 145 return ; 146 splay(time); 147 int q=f_pr(time); 148 int p=f_ne(time); 149 int mi=inf; 150 if(q!=-1) 151 mi=min(mi,abs(tree[q].w-w)); 152 if(p!=-1) 153 mi=min(mi,abs(tree[p].w-w)); 154 sum+=mi; 155 } 156 int main() 157 { 158 int n; 159 while(scanf("%d",&n)!=EOF) 160 { 161 scanf("%d",&sum); 162 time=1; 163 tree[time].fa=tree[time].l=tree[time].r=-1; 164 tree[time].w=sum; 165 root=time; 166 for(int i=1;i<n;i++) 167 { 168 int a; 169 scanf("%d",&a); 170 Insert(a); 171 } 172 printf("%d ",sum); 173 } 174 return 0; 175 }