帶權并查集按秩合并即可維護。

#include<iostream> #include<cstdio> #include<cmath> #include<cstdlib> #include<cstring> #include<algorithm> using namespace std; #define ll long long char getc(){char c=getchar();while ((c<'A'||c>'Z')&&(c<'a'||c>'z')) c=getchar();return c;} int gcd(int n,int m){return m==0?n:gcd(m,n%m);} int read() {int x=0,f=1;char c=getchar();while (c<'0'||c>'9') {if (c=='-') f=-1;c=getchar();}while (c>='0'&&c<='9') x=(x<<1)+(x<<3)+(c^48),c=getchar();return x*f; } #define N 100010 int n,m,fa[N],deep[N],weight[N],len[N]; int find(int x) {if (fa[x]==x) return x;int p=find(fa[x]);weight[x]=weight[fa[x]]+len[x];return p; } void merge(int x,int y,int z) {int p=find(x),q=find(y);if (p!=q){if (deep[p]<deep[q]) swap(p,q),swap(x,y),z=-z;fa[q]=p;if (deep[p]==deep[q]) deep[p]++;weight[q]=len[q]=weight[x]-weight[y]-z;} } int main() { #ifndef ONLINE_JUDGEfreopen("bzoj4690.in","r",stdin);freopen("bzoj4690.out","w",stdout);const char LL[]="%I64d\n"; #elseconst char LL[]="%lld\n"; #endifn=read(),m=read();while (n){for (int i=1;i<=n;i++) fa[i]=i,deep[i]=1,weight[i]=len[i]=0;while (m--){char c=getchar();while (c!='!'&&c!='?') c=getchar();if (c=='!'){int x=read(),y=read(),z=read();merge(x,y,z);}else{int x=read(),y=read();if (find(x)!=find(y)) printf("UNKNOWN\n");else printf("%d\n",weight[x]-weight[y]);}}n=read(),m=read();}return 0; }

?

轉載于:https://www.cnblogs.com/Gloid/p/9914802.html

總結

以上是生活随笔為你收集整理的BZOJ4690 Never Wait for Weights（并查集）的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。