【线段树】line

。。水题。。。

#include <cstdio>#include <iostream>using namespace std;int read(){int n = 0, sign = 1; char c = getchar();while(c < '0' || c > '9') {if(c == '-') sign = -1; c = getchar(); }while(c >= '0' && c <= '9') { n = n*10 + c-'0'; c = getchar(); }return n * sign;}const int Nmax = 100005;const int Mmax = 100005;int N, M;bool is_line[Mmax];struct line{int l, r, h, R;}li[Mmax];int q[Mmax];inline void Union(int a, int b){int temp = li[a].R;li[a].R = b; li[b].R = temp;}#define lc (u << 1)#define rc (u << 1 | 1)namespace SegmentTree{int lazyc[4 * Nmax], lazyh[4 * Nmax];inline void push_down(int u){if (lazyh[lc] < lazyh[u]) {lazyh[lc] = lazyh[u];lazyc[lc] = lazyc[u];}if (lazyh[rc] < lazyh[u]){lazyh[rc] = lazyh[u];lazyc[rc] = lazyc[u];}lazyh[u] = lazyc[u] = 0;}inline void Add(int u, int l, int r, int L, int R, int color, int high){if (lazyh[u] > high) return;if (L == l && r == R){lazyc[u] = color;lazyh[u] = high;return;}int mid = (l + r) >> 1; push_down(u);if (R <= mid) Add(lc, l, mid, L, R, color, high);else if (L > mid) Add(rc, mid + 1, r, L, R, color, high);else {Add(lc, l, mid, L, mid, color, high);Add(rc, mid + 1, r, mid + 1, R, color, high); }}inline int Query(int u, int l, int r, int pos){if (l == r) return lazyc[u];int mid = (l + r) >> 1; push_down(u);if (pos <= mid) return Query(lc, l, mid, pos);else return Query(rc, mid + 1, r, pos);}}int main(){freopen("line.in", "r", stdin);freopen("line.out", "w", stdout);N = read(), M = read();int cnt1 = 0, cnt2 = 0;li[0].h = li[0].R = -1;for (int i = 1; i <= M; ++i){int sign = read();if (sign == 1) {is_line[i] = 1; ++cnt1;li[cnt1].l = read(), li[cnt1].r = read(); int lower = read();Union(lower, cnt1);} else q[++cnt2] = read();}for (int i = 0, cnt = 0; ~i; i = li[i].R, ++cnt) li[i].h = cnt;using namespace SegmentTree; cnt1 = cnt2 = 0;for (int i = 1; i <= M; ++i) {if(is_line[i]){line temp = li[++cnt1];Add(1, 1, N, temp.l, temp.r, cnt1, temp.h);} else printf("%d\n", Query(1, 1, N, q[++cnt2]));}return 0;}