bnu36905 Nested Segments 离散化+线段树

bnu36905 Nested Segments

离散化+线段树区间更新

也可以用离散化+set（或双向链表）

#include <cstdio>#include <ctime>#include <cstdlib>#include <cstring>#include <queue>#include <string>#include <set>#include <stack>#include <map>#include <cmath>#include <vector>#include <iostream>#include <algorithm>#include <bitset>#include <fstream>using namespace std;//LOOP#define FF(i, a, b) for(int i = (a); i < (b); ++i)#define FE(i, a, b) for(int i = (a); i <= (b); ++i)#define FED(i, b, a) for(int i = (b); i>= (a); --i)#define REP(i, N) for(int i = 0; i < (N); ++i)#define CLR(A,value) memset(A,value,sizeof(A))#define FC(it, c) for(__typeof((c).begin()) it = (c).begin(); it != (c).end(); it++)//OTHER#define SZ(V) (int)V.size()#define PB push_back#define MP make_pair#define all(x) (x).begin(),(x).end()//INPUT#define RI(n) scanf("%d", &n)#define RII(n, m) scanf("%d%d", &n, &m)#define RIII(n, m, k) scanf("%d%d%d", &n, &m, &k)#define RIV(n, m, k, p) scanf("%d%d%d%d", &n, &m, &k, &p)#define RV(n, m, k, p, q) scanf("%d%d%d%d%d", &n, &m, &k, &p, &q)#define RS(s) scanf("%s", s)#define sqr(x) (x) * (x)typedef long long LL;typedef unsigned long long ULL;typedef vector <int> VI;const int INF = 0x3f3f3f3f;const double EPS = 1e-9;const int MOD = 1000000007;const double PI = acos(-1.0);const int maxn = 410000;#define ll rt << 1#define rr rt << 1 | 1struct Node{    int l, r, m;    int val;}st[maxn << 2];void build(int l, int r, int rt){    st[rt].l = l; st[rt].r = r;    int m = (l + r) >> 1; st[rt].m = m;    st[rt].val = -1;    if (l == r) return ;    build(l, m, ll); build(m + 1, r, rr);}inline void segVal(int rt, int x){    st[rt].val = x;}inline void down(int rt){    if (st[rt].val != -1)    {        segVal(ll, st[rt].val);        segVal(rr, st[rt].val);        st[rt].val = -1;    }}void update(int L, int R, int x, int rt){    if (L <= st[rt].l && st[rt].r <= R)    {        segVal(rt, x);        return ;    }    down(rt);    if (L <= st[rt].m) update(L, R, x, ll);    if (R > st[rt].m) update(L, R, x, rr);}int query(int p, int rt){    if (st[rt].l == st[rt].r)        return st[rt].val;    down(rt);    if (p <= st[rt].m) return query(p, ll);    else return query(p, rr);}int n;struct Seg{    int l, r;    int id;    bool operator<(const Seg &rhs) const{        return r - l > rhs.r - rhs.l;    }}seg[100010];int a[maxn];int asz;int main(){    while (~RI(n))    {        asz = 0;        REP(i, n)        {            scanf("%d%d", &seg[i].l, &seg[i].r);            a[asz++] = seg[i].l; a[asz++] = seg[i].r;            seg[i].id = i + 1;        }        sort(seg, seg + n);        ///离散化start        a[asz++] = 0; a[asz++] = 1e9 + 1;        sort(a, a + asz);        asz = unique(a, a + asz) - a;        int atot = asz;        for (int i = 1; i < asz; i++)        {            if (a[i] - a[i - 1] > 1) a[atot++] = a[i] - 1;///        }        asz = atot;        sort(a, a + asz);        ///离散化end        build(1, asz, 1);        for (int i = 0; i < n; i++)        {            int L = lower_bound(a, a + asz, seg[i].l) - a;            int R = lower_bound(a, a + asz, seg[i].r) - a;            update(L + 1, R + 1, seg[i].id, 1);        }        int q;        RI(q);        while (q--)        {            int x;            RI(x);            int xx = lower_bound(a, a + asz, x) - a;            printf("%d\n", query(xx + 1, 1));        }    }    return 0;}