ZOJ 2112 Dynamic Rankings

参考：

http://blog.csdn.net/acm_cxlove/article/details/8565309

http://www.cnblogs.com/Rlemon/archive/2013/05/24/3096264.html

http://www.cnblogs.com/kuangbin/p/3308118.html

http://seter.is-programmer.com/posts/31907.html

#include <iostream>#include <cstdio>#include <cstring>#include <queue>#include <vector>#include <algorithm>#define lowbit(x) (x&(-x))using namespace std;const int N = 60005;const int M = N * 40;//前几次用了30倍   WA了几发const int MM = 10005;int n,m,q,tot;int a[N],t[N];int T[N],ls[M],rs[M],c[M],use[N],s[N];struct Question{int kind, l, r, k;}que[MM];void Init_hash(){sort(t+1,t+m+1);m = unique(t+1,t+1+m)-t-1;}int hash(int x){return lower_bound(t+1,t+1+m,x)-t;}void build(int l, int r, int &rt){rt = tot ++;c[rt] = 0;if(l != r){int mid = (l+r)>>1;build(l, mid, ls[rt] );build(mid+1, r, rs[rt]);}}int update(int root, int pos, int val){int newroot = tot++, tmp = newroot;c[newroot] = c[root] + val;int l = 1, r = m;while(l < r){int mid = (l+r)>>1;if(pos <= mid){ls[newroot] = tot++;rs[newroot] = rs[root];newroot = ls[newroot];root = ls[root];r = mid;}else {rs[newroot] = tot++;ls[newroot] = ls[root];newroot = rs[newroot];root = rs[root];l = mid+1;}c[newroot] = c[root] + val;}return tmp;}void Modify(int x, int pos, int val){while(x<=n){s[x] = update(s[x],pos,val);x += lowbit(x);}}int sum(int x){int ret = 0;while(x>0){ret += c[ls[use[x]]];x -= lowbit(x);}return ret;}int query(int left, int right, int k){int left_root = T[left-1], right_root = T[right];int l = 1, r = m;for(int i = left-1; i; i -= lowbit(i))use[i] = s[i];for(int i = right;  i; i -= lowbit(i))use[i] = s[i];while(l < r){int mid = (l+r)>>1;int cot = sum(right) - sum(left-1) + c[ls[right_root]] - c[ls[left_root]];if(cot >= k){r = mid;left_root = ls[left_root];right_root = ls[right_root];for(int i = left-1; i; i -= lowbit(i))use[i] = ls[use[i]];for(int i = right;  i; i -= lowbit(i))use[i] = ls[use[i]];}else {l = mid+1;k -= cot;left_root = rs[left_root];right_root = rs[right_root];for(int i = left-1; i; i -= lowbit(i))use[i] = rs[use[i]];for(int i = right;  i; i -= lowbit(i))use[i] = rs[use[i]];}}return l;}int main(){char str[5];int l,r,k,ks;//freopen("in.txt","r",stdin);scanf("%d",&ks);while(ks--){scanf("%d%d",&n, &q);tot = m = 0;for(int i = 1; i <= n; i++ ){scanf("%d", a+i);t[++m] = a[i];}for(int i = 0; i < q; i++){scanf("%s",str);if(str[0] == 'Q'){scanf("%d%d%d", &l, &r, &k);que[i] = Question{0, l, r, k};}else {scanf("%d%d", &l, &k);que[i] = Question{1, l, 0, k};t[++m] = k;}}Init_hash();build(1,m,T[0]);for(int i = 1; i <= n; i++){T[i] = update(T[i-1], hash(a[i]), 1);s[i] = T[0];}for(int i = 0; i < q; i++){if(que[i].kind == 0){printf("%d\n",t[query(que[i].l,que[i].r,que[i].k)]);}else {Modify(que[i].l,hash(a[que[i].l]),-1);Modify(que[i].l,hash(que[i].k),1);a[que[i].l] = que[i].k;}}}return 0;}