1.Tarjan O(n+q) HDU - 2586
#include #include #include #include #include #include #include #include #include #define FRER() freopen("in.txt","r",stdin) #define FREW() freopen("out.txt","w",stdout) #define go int T;cin>>T;for(int kase=0;kase pii; const int maxn = 40000 + 7; int n,m,nEdge; int to[maxn*2],nxt[maxn*2],w[maxn*2],head[maxn],ans[maxn],d[maxn],f[maxn],vis[maxn]; struct Node { int to,id; }; void addEdge(int u,int v,int c){to[nEdge] = v;nxt[nEdge] = head[u];w[nEdge] = c;head[u] = nEdge++;} int Find(int u){return u==f[u]?u:f[u]=Find(f[u]);} vectorq[maxn]; void Init(){ nEdge = 0; memset(d, 0, sizeof(d)); memset(vis, 0, sizeof(vis)); memset(ans, 0, sizeof(ans)); memset(head, -1, sizeof(head)); for(int i=0;i<=n;i++) f[i] = i; for(int i=0;i<=n;i++) q[i].clear(); } void LCA(int u,int dis){ vis[u] = 1; d[u] = dis; for(int e=head[u];~e;e=nxt[e]){ int v = to[e]; if(vis[v]) continue; LCA(v, dis + w[e]); int uu = Find(u); int vv = Find(v); if(uu!=vv) f[vv] =uu; } int len = (int)q[u].size(); for(int i=0;i
2.倍增 O((n+q)logn) ZOJ - 3195
#include #include #include #include #include #include #include #include #include #define FRER() freopen("in.txt","r",stdin) #define FREW() freopen("out.txt","w",stdout) #define go int T;cin>>T;for(int kase=0;kase pii; const int maxn = 50000 + 7; int n,m,nEdge; int to[maxn*2],nxt[maxn*2],w[maxn*2],head[maxn],d[maxn],f[maxn],vis[maxn],depth[maxn]; void addEdge(int u,int v,int c){to[nEdge] = v;nxt[nEdge] = head[u];w[nEdge] = c;head[u] = nEdge++;} void Init(){ nEdge = 0; memset(d, 0, sizeof(d)); memset(vis, 0, sizeof(vis)); memset(head, -1, sizeof(head)); } void dfs(int u,int d1,int d2,int pre){ f[u] = pre; d[u] = d1; depth[u] = d2; vis[u] = 1; for(int e = head[u];~e;e=nxt[e]){ int v = to[e]; if(vis[v]) continue; dfs(v, d1+w[e], d2+1,u); } } int LCA(int u,int v){ int uu = u , vv = v; if(depth[u]>depth[v]) swap(u,v); while(depth[v]>depth[u]) v = f[v]; while(u!=v){ u = f[u]; v = f[v]; } return d[uu]+d[vv]-2*d[u]; } int main(){ //FRER(); //FREW(); int k = 0; while(~scanf("%d",&n)){ if(k++) cout<
3.RMQ O(nlogn) POJ - 1986
#include #include #include #include #include #include #include #include #include #define FRER() freopen("in.txt","r",stdin) #define FREW() freopen("out.txt","w",stdout) #define go int T;cin>>T;for(int kase=0;kase pii; const int maxn = 50000 + 7; int n,m,nEdge,tot; int to[maxn*2],nxt[maxn*2],w[maxn*2],head[maxn],d[maxn],f[maxn],vis[maxn],depth[maxn],st[maxn<<1][20],in[maxn]; void addEdge(int u,int v,int c){to[nEdge] = v;nxt[nEdge] = head[u];w[nEdge] = c;head[u] = nEdge++;} void Init(){ nEdge = tot = 0; memset(d, 0, sizeof(d)); memset(vis, 0, sizeof(vis)); memset(head, -1, sizeof(head)); } void dfs(int u,int d1,int d2,int pre){ f[u] = pre; d[u] = d1; depth[u] = d2; vis[u] = 1; st[++tot][0] = u; in[u] = tot; for(int e = head[u];~e;e=nxt[e]){ int v = to[e]; if(vis[v]) continue; dfs(v, d1+w[e], d2+1,u); st[++tot][0] = u; } } void getST(){ for (int j = 1; (1 << j) <= tot; j++) { for (int i = 1; i + (1 << j) - 1 <= tot; i++) { int ans1 = depth[st[i][j - 1]]; int ans2 = depth[st[i + (1 << (j - 1))][j - 1]]; if(ans1in[v]) swap(u, v); printf("%d\n",d[u]+d[v]-2*d[RMQ(in[u], in[v])]); } } return 0; }
