题意：一棵N个结点(编号从0开始)的树，根结点为0，求到根结点的距离大于D的结点个数（0 < 测试组数T <= 10, 0<N<=100000, 0<D<N）。
题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=4707
——>>统计吧。。。
#include <cstdio>
#include <cstring>using namespace std;const int maxn = 100000 + 10;int D, head[maxn], nxt[maxn<<1], v[maxn<<1], ecnt, d[maxn], ret;void init(){memset(head, -1, sizeof(head));ecnt = 0;ret = 0;
}void addEdge(int uu, int vv){v[ecnt] = vv;nxt[ecnt] = head[uu];head[uu] = ecnt;ecnt++;
}void dfs(int x, int fa){if(d[x] > D) ret++;for(int e = head[x]; e != -1; e = nxt[e]) if(v[e] != fa){d[v[e]] = d[x] + 1;dfs(v[e], x);}
}void solve(){d[0] = 0;dfs(0, -1);printf("%d\n", ret);
}int main()
{int T, N, uu, vv;scanf("%d", &T);while(T--){init();scanf("%d%d", &N, &D);for(int i = 0; i < N-1; i++){scanf("%d%d", &uu, &vv);addEdge(uu, vv);addEdge(vv, uu);}solve();}return 0;
}
