[HDU5361]In Touch
[HDU5361]In Touch
题目大意:
有\(n(n\le2\times10^5)\)个点,每个点有三个属性\(l_i,r_i,c_i\)。表示若\(|i-j|\in[l_i,r_i]\),\(i\)到\(j\)有一条长度为\(c_i\)的单向边。求从\(1\)出发到各个点的距离。
思路:
线段树优化建图后跑Dijkstra即可。
源代码:
#include<cstdio>
#include<cctype>
#include<vector>
#include<climits>
#include<functional>
#include<ext/pb_ds/priority_queue.hpp>
inline int getint() {
register char ch;
while(!isdigit(ch=getchar()));
register int x=ch^'0';
while(isdigit(ch=getchar())) x=(((x<<2)+x)<<1)+(ch^'0');
return x;
}
const int N=4e5+1;
typedef long long int64;
int tot,l[N],r[N],c[N],pos[N];
struct Edge {
int to,w;
};
std::vector<Edge> e[N];
inline void add_edge(const int &u,const int &v,const int &w) {
e[u].push_back((Edge){v,w});
}
inline void reset() {
for(register int i=1;i<=tot;i++) {
e[i].clear();
}
tot=0;
}
class SegmentTree {
#define mid ((b+e)>>1)
private:
struct Node {
int left,right;
};
Node node[N];
int new_node() {
node[++tot]=(Node){};
return tot;
}
public:
int root;
void build(int &p,const int &b,const int &e) {
p=new_node();
if(b==e) {
pos[b]=p;
return;
}
build(node[p].left,b,mid);
build(node[p].right,mid+1,e);
add_edge(p,node[p].left,0);
add_edge(p,node[p].right,0);
}
void link(const int &p,const int &b,const int &e,const int &l,const int &r,const int &x,const int &y) const {
if(l>r) return;
if(b==l&&e==r) {
add_edge(x,p,y);
return;
}
if(l<=mid) link(node[p].left,b,mid,l,std::min(mid,r),x,y);
if(r>mid) link(node[p].right,mid+1,e,std::max(mid+1,l),r,x,y);
}
#undef mid
};
SegmentTree sgt;
struct Vertex {
int id;
int64 dis;
bool operator > (const Vertex &rhs) const {
return dis>rhs.dis;
}
};
int64 dis[N];
__gnu_pbds::priority_queue<Vertex,std::greater<Vertex> > q;
__gnu_pbds::priority_queue<Vertex,std::greater<Vertex> >::point_iterator p[N];
inline void dijkstra() {
for(register int i=1;i<=tot;i++) {
p[i]=q.push((Vertex){i,dis[i]=i==pos[1]?0:LLONG_MAX});
}
while(!q.empty()&&q.top().dis!=LLONG_MAX) {
const int x=q.top().id;
q.pop();
for(register unsigned i=0;i<e[x].size();i++) {
const int &y=e[x][i].to,&w=e[x][i].w;
if(dis[x]+w<dis[y]) {
q.modify(p[y],(Vertex){y,dis[y]=dis[x]+w});
}
}
}
q.clear();
}
int main() {
for(register int T=getint();T;T--) {
const int n=getint();
sgt.build(sgt.root,1,n);
for(register int i=1;i<=n;i++) l[i]=getint();
for(register int i=1;i<=n;i++) r[i]=getint();
for(register int i=1;i<=n;i++) c[i]=getint();
for(register int i=1;i<=n;i++) {
sgt.link(1,1,n,std::max(1,i-r[i]),i-l[i],pos[i],c[i]);
sgt.link(1,1,n,i+l[i],std::min(i+r[i],n),pos[i],c[i]);
}
dijkstra();
for(register int i=1;i<=n;i++) {
printf("%lld%c",dis[pos[i]]!=LLONG_MAX?dis[pos[i]]:-1," \n"[i==n]);
}
reset();
}
return 0;
}