[HDU] Mayor's posters (line segment tree interval problem)

Discretization is required, and the interval of the Line Segment tree is modified.

Note that when discretization is performed, special processing is required because the given number is a unit length (because the coverage of a line segment is different from that of a point)

For example)

After discretization, values 1, 4, 6, and 10 are discrete to 1, 2, 3, and 4 respectively.

Overwrite 1 4, overwrite 1 2, overwrite 2 3, and the result is 2.

But it should actually be 3

13450359

201301052100

2528

Accepted

1140 K

985 Ms

C ++

1960b

15:42:33

985ms insurance.

# Include <cstdio> # include <cstring> # include <iostream> # include <algorithm> # include <vector> # include <queue> # include <map> using namespace STD; typedef long ll; const int maxn = 11111; int n, m, ans; bool vis [maxn]; int arr [maxn <2]; int arr_l [maxn]; int arr_r [maxn]; int tr [maxn <4]; void Update (int l, int R, int value, int L, int R, int POS) {If (L <= L & R <= r) {tr [POS] = value; return;} If (TR [POS]! =-1) {tr [POS <1] = tr [POS]; tr [(Pos <1) | 1] = tr [POS]; tr [POS] =-1;} int M = (L + r)> 1; if (L <= m) Update (L, R, value, L, M, pos <1); If (r> m) Update (L, R, value, m + 1, R, (Pos <1) | 1); return ;} void query (int l, int R, int POS) {If (TR [POS]! =-1) {int e = tr [POS]; If (! Vis [e]) {vis [e] = true; ans ++;} return;} If (L = r) return; int M = (L + r)> 1; query (L, M, POS <1); query (m + 1, R, (Pos <1) | 1); return;} int main () {int t; scanf ("% d", & T); While (t --) {memset (VIS, false, sizeof (VIS); memset (TR,-1, sizeof (TR); scanf ("% d", & M); int size = 0; For (INT I = 0; I <m; I ++) {scanf ("% d", & arr_l [I], & arr_r [I]); arr [size ++] = arr_l [I]; arr [size ++] = arr_r [I];} Sort (ARR, arr + size); n = unique (ARR, arr + size)-Arr; // deduplicated for (INT I = n-1; I> 0; I --) // convert the interval to a vertex if (ARR [I]! = Arr [I-1] + 1) Arr [n ++] = arr [I-1] + 1; sort (ARR, arr + n); ans = 0; for (INT I = 0; I <m; I ++) {int L = find (ARR, arr + N, arr_l [I])-Arr; // Binary Search int r = find (ARR, arr + N, arr_r [I])-Arr; // Binary Search Update (L, R, I, 0, n-);} query (0, N-); printf ("% d \ n", ANS);} return 0 ;}

[HDU] Mayor's posters (line segment tree interval problem)