hdu5860 Death Sequence

这题一开始写的线段数是从中间开始查找 k个 导致是nlogn 每次查找应该都是从头找每次找的个数不同就好了

还有一种递推的写法我放下面了

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MAXN = 3e6+5;
const int MOD = 1e9+7;

int N,K,Q;
int ans[MAXN];
int turn[MAXN];
int dp[MAXN];
int a[MAXN];
int main(){
	int T; scanf("%d",&T);
	while(T--) {
		scanf("%d %d %d",&N,&K,&Q);

		int tt = N;
		int tot = 0;
		turn[0] = 0;
		while(tt) {
			++tot;
			turn[tot] = turn[tot-1] + (tt-1) / K + 1;
			tt = tt-1-(tt-1)/K;
		}

		for(int i = 0; i < N; ++i) {
			dp[i] = i%K? dp[i - i/K -1]+1 : 0;
			a[i]  = i%K? a[i - i/K -1] : i/K+1;
		}
		for(int i = 0; i < N; ++i) {
			int tmp = turn[dp[i]] + a[i];
			ans[tmp] = i+1;
		}

		for(int i = 0; i < Q; ++i) {
			int a; scanf("%d",&a);
			printf("%d\n",ans[a]);
		}
	}
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
const int MAXN = 3e6+5;
int N,K,Q;
int tree[MAXN<<2];
int st[MAXN];
void Build(int l,int r,int rt){
	tree[rt] = r-l+1;
	if(l == r) {
		return;
	}
	int m = (l+r)>>1;
	Build(lson); Build(rson);
}

int Ed;
void Find(int sum,int l,int r,int rt) {
	if(l == r) {
		tree[rt] = 0; Ed = r; return;
	}
	int m = (l+r) >>1;
	if(tree[rt<<1] >= sum) Find(sum,lson);
	else Find(sum-tree[rt<<1],rson);
	tree[rt] = tree[rt<<1] + tree[rt<<1|1];
}

int main(){
	int T; scanf("%d",&T);
	while(T--){
		memset(tree,0,sizeof(tree));
		scanf("%d %d %d",&N,&K,&Q);
		Build(1,N,1);

		int sz = N; int cnt = 0;
		while(sz>0) {
			int mx = (sz-1)/K;
			for(int i = 0; i <= mx; ++i) {
				int sum = 1+i*K-i;
				Find(sum,1,N,1);
				st[++cnt] = Ed; sz--;
			}
		}

		for(int i = 1; i <= Q; ++i){
			int a; scanf("%d",&a);
			printf("%d\n",st[a]);
		}
	}
	return 0;
}