洛谷P5057 [CQOI2006]簡單題(線段樹)
阿新 • • 發佈:2018-12-07
題意
Sol
紫色的線段樹板子題??。。。
#include<iostream> #include<cstdio> #include<cmath> using namespace std; const int MAXN = 1e6 + 10; inline int read() { char c = getchar(); int x = 0, f = 1; while (c < '0' || c > '9') {if (c == '-')f = -1; c = getchar();} while (c >= '0' && c <= '9') {x = x * 10 + c - '0'; c = getchar();} return x * f; } int N, M; #define ls k << 1 #define rs k << 1 | 1 struct Node { int l, r, w, f; }T[MAXN]; void Build(int k, int ll, int rr) { T[k].l = ll; T[k].r = rr; T[k].w = -1; T[k].f = 0; if(ll == rr) {T[k].w = 0; return ;} int mid = (T[k].l + T[k].r) >> 1; Build(ls, ll, mid); Build(rs, mid + 1, rr); } void Reverse(int k, int ll, int rr) { if(ll <= T[k].l && T[k].r <= rr) {T[k].f ^= 1; return ;} int mid = (T[k].l + T[k].r) >> 1; if(ll <= mid) Reverse(ls, ll, rr); if(rr > mid) Reverse(rs, ll, rr); } int Query(int k, int pos) { int ans = T[k].f; if(T[k].l == T[k].r) return ans; int mid = (T[k].l + T[k].r) >> 1; if(pos <= mid) ans ^= Query(ls, pos); if(pos > mid) ans ^= Query(rs, pos); return ans; } int main() { N = read(); M = read(); Build(1, 1, N); while(M--) { int opt = read(); if(opt == 1) { int l = read(), r = read(); Reverse(1, l, r); } else { printf("%d\n", Query(1, read())); } } return 0; }