Codeforces 558E A Simple Task segment Tree

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Test instructions is relatively simple.

Ideas:

Because there are only 26 letters, it is easier to maintain them with 26 tree segments.

#include <iostream> #include <string> #include <vector> #include <cstring> #include <cstdio > #include <map> #include <queue> #include <algorithm> #include <stack> #include <cstring > #include <cmath> #include <set> #include <vector>using namespace std;template <class t>  inline BOOL Rd (T &ret) {char c; int sgn;if (c = GetChar (), c = = EOF) return 0;while (c! = '-' && (c< ' 0 ' | | C> ' 9 ')) C = GetChar (); sgn = (c = = '-')? -1:1;ret = (c = = '-')? 0: (C-' 0 '); while (c = GetChar (), C >= ' 0 ' &&c <= ' 9 ') ret = ret * + (C-' 0 '); ret *= Sgn;return 1;} Template <class t>inline void pt (T x) {if (x <0) {Putchar ('-'); x = x;} if (x>9) pt (X/10);p Utchar (x% 10 + ' 0 ');} typedef long Long Ll;typedef pair<ll, ll> pii;const int N = 1e5 +, #define Lson (id<<1) #define Rson (id< <1|1) #define L (x) tree[x].l#define R (x) tree[x].r#define Hav (x) tree[x].hav#define Siz (x) tree[x].Siz#define Lazy (x) tree[x].lazystruct tree {struct Node {int L, R, Siz;//siz indicates interval length int hav;//hav indicates this interval and int lazy;//lazy is 2 table The empty interval, lazy 1, indicates that the interval is changed to 1}tree[n << 2];void build (int l, int r, int id) {L (id) = l; R (ID) = R; Siz (id) = r-l + 1; Hav (id) = Lazy (id) = 0;if (L = = r) Return;int mid = (L + R) >> 1;build (L, Mid, Lson); Build (mid + 1, R, Rson);} void down (int id) {if (lazy (id) = = 1) {lazy (id) = 0; Hav (Lson) = Siz (Lson); Hav (Rson) = Siz (Rson); Lazy (Lson) = Lazy (Rson) = 1;} else if (lazy (id) = = 2) {lazy (id) = 0; HAV (Lson) = hav (Rson) = 0; Lazy (Lson) = Lazy (Rson) = 2;}} void up (int id) {hav (id) = hav (Lson) + hav (Rson);} void Updata (int l, int r, int val, int id) {if (L = = L (ID) && r (id) = = r) {if (val = = 1) Hav (id) = Siz (ID); else Ha V (id) = 0; Lazy (id) = Val;return;} Down (ID); int mid = (L (ID) + R (ID)) >> 1;if (R <= Mid) Updata (L, R, Val, Lson), else if (Mid < L) Updata (L, R, Val , Rson); else {Updata (L, Mid, Val, Lson); Updata (mid + 1, R, Val, Rson);} Up (ID);} int query (int l, int r, int id) {if (L = = L (ID) && r (id) = = r) {return Hav (ID);} Down (ID); int mid = (L (ID) + R (ID)) >> 1, ans = 0;if (R <= mid) ans = query (l, R, Lson); else if (Mid < L) ans = q Uery (L, R, Rson), else {ans = query (l, Mid, Lson) + query (mid + 1, R, Rson);} Up (ID); return ans;}; Tree alph[26];int N, Q;char s[n];int sum[26];int Main () {rd (n); Rd (q); for (int i = 0; i <; i++) Alph[i].build (1, N, 1 ); scanf ("%s", S + 1), for (int i = 1; I <= n; i++) {alph[s[i]-' A '].updata (i, I, 1, 1);} while (q--) {int L, R, In;rd (l); Rd (R); Rd (in); memset (sum, 0, sizeof sum); for (int i = 0; i <; i++) {Sum[i] + = Alph[i ].query (L, R, 1); Alph[i].updata (L, R, 2, 1);} int Tim = n, i;if (in) i = 0; else I = +, in = -1;for (; tim--; i + = in) {if (sum[i] = = 0) continue;alph[i].updata (l, L + sum[i]-1, 1, 1); L + = sum[i];} }for (int i = 1; I <= n; i++) {for (int j = 0; J <; J + +) if (Alph[j].query (i, I, 1)) {Putchar (j + ' a '); return 0;}

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Codeforces 558E A Simple Task segment Tree