【CCF】商路
【60分】
1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<string> 5 #include<cmath> 6 #include<algorithm> 7 #include<queue> 8 #include<map> 9 using namespace std; 10 typedef long long ll; 11 const int maxn=1e5+2; 12 const int maxm=maxn; 13 const ll mod=1e18; 14 int fa[maxn]; 15 ll dep[maxn]; 16 ll dp[maxn]; 17 struct node{ 18 ll v; 19 ll f; 20 }g[maxn]; 21 struct edge{ 22 int to; 23 int nxt; 24 ll w; 25 }e[2*maxm]; 26 int tot; 27 int n; 28 29 int head[maxn]; 30 void init(){ 31 memset(head,-1,sizeof(head)); 32 tot=0; 33 memset(dp,-1,sizeof(dp)); 34 memset(dep,0,sizeof(dep)); 35 } 36 void add(int u,int v,ll w){ 37 e[tot].to=v; 38 e[tot].w=w; 39 e[tot].nxt=head[u]; 40 head[u]=tot++; 41 } 42 ll dis(int u,int v){ 43 ll tmp=g[u].f-(dep[v]-dep[u]); 44 tmp=tmp*tmp; 45 tmp=g[u].v-tmp; 46 return tmp; 47 } 48 void update(int son,int u){ 49 if(u==0) return; 50 dp[u]=max(dp[u],dp[son]+dis(u,son)); 51 update(son,fa[u]); 52 } 53 void dfs(int u){ 54 for(int i=head[u];i!=-1;i=e[i].nxt){ 55 int v=e[i].to; 56 if(v<u) continue; 57 dfs(v); 58 } 59 if(dp[u]==-1) dp[u]=0; 60 update(u,fa[u]); 61 } 62 void getdepth(int u){ 63 for(int i=head[u];i!=-1;i=e[i].nxt){ 64 int v=e[i].to; 65 ll w=e[i].w; 66 if(v<u) continue; 67 dep[v]=dep[u]+w; 68 getdepth(v); 69 } 70 } 71 ll work(){ 72 getdepth(1); 73 dfs(1); 74 ll ans=0; 75 for(int i=1;i<=n;i++){ 76 ans=(ans+dp[i])%mod; 77 } 78 return ans; 79 } 80 int main(){ 81 int T; 82 scanf("%d",&T); 83 while(T--){ 84 init(); 85 scanf("%d",&n); 86 int u; 87 ll d,v,f; 88 for(int i=1;i<=n;i++){ 89 scanf("%d%lld%lld%lld",&u,&d,&v,&f); 90 g[i].v=v; 91 g[i].f=f; 92 add(u,i,d); 93 add(i,u,d); 94 fa[i]=u; 95 } 96 ll ans=work(); 97 printf("%lld\n",ans); 98 } 99 return 0; 100 }
