HDU 4417 Super Mario

划分树 + 二分

二分枚举第k小的数与h比较大小。

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <algorithm>
using namespace std;
const int MAXN = 100100;
struct Node
{int l, r;
}T[MAXN << 2];int d[MAXN], s[MAXN], t[35][MAXN], tol[35][MAXN];void build(int level, int rt, int l, int r)
{int i;T[rt].l = l, T[rt].r = r;if(l == r) return;int mid = l + r >> 1;int lsame = mid - l + 1;for(i = l; i <= r; i ++){if(t[level][i] < s[mid])lsame --;}int Ll = l, Lr = mid, Rl = mid + 1, Rr = r;int Ltot = 0, Rtot = 0;for(i = l; i <= r; i ++){if(i == l)tol[level][i] = 0;elsetol[level][i] = tol[level][i - 1];if(t[level][i] < s[mid]){tol[level][i] ++;t[level + 1][Ll + Ltot ++] = t[level][i];}else if(t[level][i] > s[mid]){t[level + 1][Rl + Rtot ++] = t[level][i];}else{if(lsame > 0){lsame --;t[level + 1][Ll + Ltot ++] = t[level][i];tol[level][i] ++;}else{t[level + 1][Rl + Rtot ++] = t[level][i];}}}build(level + 1, rt << 1, Ll, Lr);build(level + 1, rt << 1 | 1, Rl, Rr);
}int query(int level, int rt, int l, int r, int k)
{if(l == r) return t[level][l];int nl, nls;if(l == T[rt].l)nls = 0;elsenls = tol[level][l - 1];nl = tol[level][r] - nls;if(nl >= k){return query(level + 1, rt << 1, T[rt].l + nls,T[rt].l + nl + nls - 1, k);}else{int mid = (T[rt].l + T[rt].r) >> 1;int nre = l - T[rt].l + 1 - nls;int nr = r - l + 1 - nl;return query(level + 1, rt << 1 | 1, mid + nre,mid + nr + nre - 1, k - nl);}
}int BS(int r, int h, int L, int R)
{int l = 0, mid;while(l < r){mid = (l + r) >> 1;if(query(1, 1, L, R, mid) > h)r = mid ;else l = mid + 1;}return l;
}int main()
{int n, m, i, T, cas;scanf("%d", &T);for(cas = 1; cas <= T; cas ++){scanf("%d%d", &n, &m);for(i = 1; i <= n; i ++){//d[i] = 1;scanf("%d", &d[i]);t[1][i] = s[i] = d[i];}sort(s + 1, s + n + 1);build(1, 1, 1, n);int l, r, h;printf("Case %d:\n", cas);while(m --){scanf("%d%d%d", &l, &r, &h);l ++, r ++;if(query(1, 1, l, r, r - l + 1) <= h)printf("%d\n", r - l + 1);else if(query(1, 1, l, r, 1) > h)puts("0");else{int tt = BS(r - l + 1, h, l, r);//printf("%d\n", tt - 1);while(query(1, 1, l, r, tt) > h){tt --;}printf("%d\n", tt);}}}return 0;
}