Poj 3225 help with intervals (line segment tree)

Poj 3225 help with intervals

Question Link

If the number of a set is 1 but not 0, the corresponding operations are set to 0, 1, or flip. You can simply push the set, then, the processing method of the open and closed intervals is to double the interval, and the even number of storage points and the odd number of storage lines can be used.

Code:

#include <cstdio>#include <cstring>#define lson(x) ((x<<1)+1)#define rson(x) ((x<<1)+2)const int N = 65536 * 2;struct Node {int l, r, flip, setv;} node[N * 4];int to[N];void build(int l, int r, int x = 0) {node[x].l = l; node[x].r = r;node[x].flip = 0; node[x].setv = -1;if (l == r) {to[l] = x;return;}int mid = (l + r) / 2;build(l, mid, lson(x));build(mid + 1, r, rson(x));}void pushdown(int x) {if (node[x].setv != -1) {node[lson(x)].setv = node[rson(x)].setv = node[x].setv;node[lson(x)].flip = node[rson(x)].flip = 0;node[x].setv = -1;}if (node[x].flip) {node[lson(x)].flip ^= 1;node[rson(x)].flip ^= 1;node[x].flip = 0;}}void add(int l, int r, int v, int x = 0) {if (l > r) return;if (node[x].l >= l && node[x].r <= r) {if (v != -1) {node[x].setv = v;node[x].flip = 0;} elsenode[x].flip ^= 1;return;}pushdown(x);int mid = (node[x].l + node[x].r) / 2;if (l <= mid) add(l, r, v, lson(x));if (r > mid) add(l, r, v, rson(x));}void query(int x = 0) {if (node[x].l == node[x].r) {if (node[x].setv == -1) node[x].setv = 0;return;}pushdown(x);int mid = (node[x].l + node[x].r) / 2;query(lson(x));query(rson(x));}char c, a, b;int l, r;int main() {build(0, N - 1);while (~scanf("%c %c%d,%d%c\n", &c, &a, &l, &r, &b)) {l = l * 2 + (a == '(');r = r * 2 - (b == ')');if (c == 'U') add(l, r, 1);if (c == 'I' || c == 'C') {add(0, l - 1, 0);add(r + 1, N - 1, 0);if (c == 'C') add(l, r, -1);}if (c == 'D') add(l, r, 0);if (c == 'S') add(l, r, -1);}query();int pre = 0, flag = 0, bo = 0;for (int i = 0; i < N; i++) {int id = to[i];int tmp = (node[id].setv^node[id].flip);if (!tmp && flag) {if (bo) printf(" ");else bo = 1;if (pre % 2) printf("(");else printf("[");printf("%d,%d", pre / 2, i / 2);if (i % 2 == 0) printf(")");else printf("]");flag = 0;} else if (tmp && !flag) {pre = i;flag = 1;}}if (bo == 0) printf("empty set");printf("\n");return 0;}

Poj 3225 help with intervals (line segment tree)