题目链接
思路:
带权并查集维护两个权,此时有两个距离需要维护,dx表示横坐标距离,dy表示纵坐标距离,
东为x方向权值 +w,南为y方向 +w,西为x方向 -w,北为y方向 -w,
因为题目要求的查询是依据前c行的并查集构建程度查询的,所以可以先把所有构建并查集数据和查询数据输入存起来,将查询数据以c的大小升序排序,遍历m行并查集构建数据,当此时idx指向的查询数据c与i相等时就查询并记录答案,最后将查询数据按输入顺序降序排序输出即可。
神奇的一A了,跑了125s,但是那个abs函数编译器不知为啥一直报错
代码:
#include#include #include #include #include #include #include #include #include #include #include #include #define fastio ios::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL) #define debug(a) cout << "debug : " << (#a) << " = " << a << endl using namespace std; typedef long long ll; typedef pair PII; const int N = 5e4 + 10; const int INF = 0x3f3f3f3f; const double eps = 1e-6; const int mod = 998244353; int n, m; int f[N], dx[N], dy[N]; struct node1 { int x, y, l; char d; } a[N]; struct node2 { int id, x, y, c, ans; } b[N]; bool cmp1(node2 x, node2 y) { return x.c < y.c; } bool cmp2(node2 x, node2 y) { return x.id < y.id; } int find(int x) { if (f[x] != x) { int u = find(f[x]); dx[x] += dx[f[x]], dy[x] += dy[f[x]]; f[x] = u; } return f[x]; } int main() { while (cin >> n >> m) { for (int i = 1; i <= n; i++) f[i] = i; for (int i = 1; i <= m; i++) scanf("%d%d%d %c", &a[i].x, &a[i].y, &a[i].l, &a[i].d); int k; cin >> k; for (int i = 1; i <= k; i++) { b[i].id = i; scanf("%d%d%d", &b[i].x, &b[i].y, &b[i].c); } sort(b + 1, b + k + 1, cmp1); int idx = 1; for (int i = 1; i <= m; i++) { int x = a[i].x, y = a[i].y, w = a[i].l, wx, wy; char op = a[i].d; if (op == 'N') { wx = 0; wy = -w; } else if (op == 'S') { wx = 0; wy = w; } else if (op == 'W') { wx = -w; wy = 0; } else { wx = w; wy = 0; } int f1 = find(x), f2 = find(y); if (f1 != f2) { f[f2] = f1; dx[f2] = dx[x] + wx - dx[y]; dy[f2] = dy[x] + wy - dy[y]; } while (b[idx].c == i) { int x = b[idx].x, y = b[idx].y; int f1 = find(x), f2 = find(y); if (f1 == f2) { b[idx].ans = 0; b[idx].ans += abs(dx[x] - dx[y]); b[idx].ans += abs(dy[x] - dy[y]); } else b[idx].ans = -1; idx++; } } sort(b + 1, b + k + 1, cmp2); for (int i = 1; i <= k; i++) cout << b[i].ans << endl; } return 0; }



