HDU 4902 Nice boat (line segment tree)

HDU Nice boat

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Question: Given a sequence, two operations are used to convert a segment into x, and each digit in a segment. If it is greater than x, it is converted into a gcd of him and x. After the change, the final sequence.

Idea: Line Segment tree. Each node has one more cover, which indicates whether the numbers in the following ranges of the position are the same. Then, each delay operation can be performed and the single point query can be performed at the end of the output.

Code:

#include
#include
#include using namespace std;const int N = 100005;#define lson(x) ((x<<1)+1)#define rson(x) ((x<<1)+2)#define INF 0x3f3f3f3fint t, n, num[N];struct Node { int l, r, x, setv; bool cover;} node[4 * N];int gcd(int a, int b) { if (!b) return a; return gcd(b, a % b);}void pushup(int x) { node[x].cover = ((node[lson(x)].x == node[rson(x)].x) && node[lson(x)].cover && node[rson(x)].cover); node[x].x = node[lson(x)].x;}void build(int l, int r, int x = 0) { node[x].l = l; node[x].r = r; node[x].setv = -1; node[x].cover = false; if (l == r) {node[x].cover = true;node[x].x = num[l];return; } int mid = (l + r) / 2; build(l, mid, lson(x)); build(mid + 1, r, rson(x)); pushup(x);}void pushdown(int x) { if (node[x].setv != -1) {node[lson(x)].setv = node[rson(x)].setv = node[x].setv;node[lson(x)].x = node[rson(x)].x = node[x].setv;node[x].setv = -1; }}void add1(int l, int r, int v, int x = 0) { if (node[x].l >= l && node[x].r <= r) {node[x].setv = v;node[x].x = v;return; } int mid = (node[x].l + node[x].r) / 2; pushdown(x); if (l <= mid) add1(l, r, v, lson(x)); if (r > mid) add1(l, r, v, rson(x)); pushup(x);}void add2(int l, int r, int v, int x = 0) { if (node[x].cover && node[x].x <= v) return; if (node[x].l >= l && node[x].r <= r && node[x].cover) {node[x].x = gcd(node[x].x, v);node[x].setv = node[x].x;return; } pushdown(x); int mid = (node[x].l + node[x].r) / 2; if (l <= mid) add2(l, r, v, lson(x)); if (r > mid) add2(l, r, v, rson(x)); pushup(x);}int query(int k, int x = 0) { if (node[x].l == node[x].r)return node[x].x; int mid = (node[x].l + node[x].r) / 2; pushdown(x); if (k <= mid) return query(k, lson(x)); if (k > mid) return query(k, rson(x));}int main() { scanf("%d", &t); while (t--) {scanf("%d", &n);for (int i = 1; i <= n; i++) scanf("%d", &num[i]);build(1, n);int q;scanf("%d", &q);int c, a, b, v;while (q--) { scanf("%d%d%d%d", &c, &a, &b, &v); if (c == 1)add1(a, b, v); else if (c == 2)add2(a, b, v);}for (int i = 1; i <= n; i++) printf("%d ", query(i));printf("\n"); } return 0;}