题意：单点更新，区间求最值。
解题思路：splay 。
解题代码：
1 // File Name: hdu1754.cpp 2 // Author: darkdream 3 // Created Time: 2015年04月03日 星期五 22时06分59秒 4 5 #include<vector> 6 #include<list> 7 #include<map> 8 #include<set> 9 #include<deque> 10 #include<stack> 11 #include<bitset> 12 #include<algorithm> 13 #include<functional> 14 #include<numeric> 15 #include<utility> 16 #include<sstream> 17 #include<iostream> 18 #include<iomanip> 19 #include<cstdio> 20 #include<cmath> 21 #include<cstdlib> 22 #include<cstring> 23 #include<ctime> 24 #define LL long long 25 26 using namespace std; 27 const int maxn = 200005; 28 struct SplayTree{ 29 int sz[maxn]; 30 int ch[maxn][2]; 31 int pre[maxn]; 32 int root ,top1,top2; 33 int ss[maxn],que[maxn]; 34 35 inline void Rotate(int x,int f){ 36 int y = pre[x]; 37 push_down(y); 38 push_down(x); 39 ch[y][!f] = ch[x][f]; 40 pre[ch[x][f]] = y ; 41 pre[x] = pre[y]; 42 if(pre[x]) ch[pre[y]][ch[pre[y]][1] == y] = x; 43 ch[x][f] = y ; 44 pre[y] = x ; 45 push_up(y); 46 } 47 inline void Splay(int x, int goal){ 48 push_down(x); 49 while(pre[x] != goal){ 50 if(pre[pre[x]] == goal){ 51 Rotate(x, ch[pre[x]][0] == x); 52 }else{ 53 int y = pre[x],z = pre[y]; 54 int f = (ch[z][0] == y); 55 if(ch[y][f] == x){ 56 Rotate(x,!f) , Rotate(x,f); 57 }else{ 58 Rotate(y,f) , Rotate(x,f); 59 } 60 } 61 } 62 push_up(x); 63 if(goal == 0) root = x; 64 } 65 inline void RotateTo(int k ,int goal){ 66 int x = root; 67 push_down(x); 68 while(sz[ch[x][0]] != k ){ 69 if(k < sz[ ch[x][0] ]){ 70 x = ch[x][0]; 71 }else{ 72 k -= (sz[ch[x][0]] + 1); 73 x = ch[x][1]; 74 } 75 push_down(x); 76 } 77 Splay(x,goal); 78 } 79 inline void erase(int x){ 80 int father = pre[x]; 81 int head = 0 , tail = 0 ; 82 for(que[tail ++] = x ; head < tail ;head ++){ 83 ss[top2++] = que[head]; 84 if(ch[que[head] ][0]) que[tail ++] = ch[que[head]][0]; 85 if(ch[que[head] ][1]) que[tail ++] = ch[que[head]][1]; 86 } 87 ch[father][ch[father][1] == x] = 0 ; 88 push_up(father); 89 } 90 inline void NewNode(int &x,int c){ 91 if(top2) x = ss[--top2]; 92 else x = ++top1; 93 ch[x][0] = ch[x][1] = pre[x] = 0 ; 94 sz[x] = 1; 95 val[x] = mx[x] = c; 96 } 97 inline void push_down(int x){ 98 99 } 100 inline void push_up(int x){ 101 sz[x] = 1 + sz[ch[x][0]] + sz[ch[x][1]]; 102 mx[x] = max(mx[ch[x][0]],val[x]); 103 mx[x] = max(mx[ch[x][1]],mx[x]); 104 } 105 inline void makeTree(int &x,int l ,int r,int f){ 106 if(l > r) return ; 107 int m = (l + r ) >> 1; 108 NewNode(x,num[m]); 109 makeTree(ch[x][0],l,m-1,x); 110 makeTree(ch[x][1],m+1,r,x); 111 pre[x] = f; 112 push_up(x); 113 } 114 inline void init(int n){ 115 ch[0][0] = ch[0][1] = pre[0] = sz[0] = 0 ; 116 mx[0] = 0 ; 117 root = top1 = 0 ; 118 NewNode(root,-1); 119 NewNode(ch[root][1],-1); 120 pre[top1] = root; 121 sz[root] = 2; 122 // printf("%d*** ",mx[root]); 123 124 for(int i = 1 ;i <= n;i ++) scanf("%d",&num[i]); 125 makeTree(ch[ch[root][1]][0],1,n,ch[root][1]); 126 push_up(ch[root][1]); 127 push_up(root); 128 129 // printf("%d*** ",mx[root]); 130 131 } 132 inline void update(int l,int v){ 133 RotateTo(l,0); 134 val[root] = v; 135 // push_up(root); 136 } 137 inline void query(int l , int r){ 138 RotateTo(l-1,0); 139 RotateTo(r+1,root); 140 printf("%d ",mx[ch[ch[root][1]][0]]); 141 } 142 int num[maxn]; 143 int mx[maxn]; 144 int val[maxn]; 145 }spt; 146 char str[10]; 147 int ta,tb; 148 int n , q; 149 int main(){ 150 while(scanf("%d %d",&n,&q) != EOF) 151 { 152 spt.init(n); 153 for(int i = 1;i <= q; i++) 154 { 155 scanf("%s %d %d",str,&ta,&tb); 156 if(str[0] == 'Q') 157 { 158 spt.query(ta,tb); 159 }else{ 160 spt.update(ta,tb); 161 } 162 } 163 } 164 return 0; 165 }