Submission #941119

#	Time	Username	Problem	Language	Result	Execution time	Memory
941119		sleepntsheep	Transport (COCI19_transport)	C11	130 / 130	411 ms	18576 KiB

Main

#include<stdio.h>

unsigned X=12345;int rand_(){return(X*=3)>>1;}
void sort(long long*aa,int l,int r)
{
    while(l<r)
    {
        int i=l,j=l,k=r;
        long long t,p=aa[l+rand_()%(r-l)];
        while(j<k)
            if(aa[j]<p)
                t=aa[i],aa[i]=aa[j],aa[j]=t,++i,++j;
            else if(aa[j]==p)
                ++j;
            else
                t=aa[--k],aa[k]=aa[j],aa[j]=t;
        sort(aa,l,i);
        l=k;
    }
}

int t[1<<19];

void _u(int p,int k) { for(;p;p-=p&-p)t[p]+=k; }

int _q(int p) { int z=0; for(;p<sizeof t/sizeof*t;p+=p&-p)z+=t[p]; return z; }

long long cc[1<<19];
int co;

int lb(long long x)
{
    int l=0,r=co-1;
    while(l<=r)
    {
        int m=(l+r)/2;
        if(cc[m]>=x)r=m-1;
        else l=m+1;
    }
    return r+1+1;
}

long long hi(long long a,long long b) { return a>b?a:b; }
long long lo(long long a,long long b) { return a<b?a:b; }

int n,a[100001],e[200002][3],ne,h[100001],ded[100001],sz[100001];
long long ll[100001],mm[100001],ll2[100001],mm2[100001],z;

void dfs(int u,int p)
{
    sz[u]=1;for(int j=h[u];j;j=e[j][2])if(e[j][0]-p&&!ded[e[j][0]])dfs(e[j][0],u),sz[u]+=sz[e[j][0]];
}

int cen(int u,int p,int tn)
{
    for(int j=h[u];j;j=e[j][2])if(e[j][0]-p&&!ded[e[j][0]]&&sz[e[j][0]]*2>=tn)return cen(e[j][0],u,tn);
    return u;
}

void dfs2(int u,int p)
{
    for(int j=h[u];j;j=e[j][2])if(e[j][0]-p&&!ded[e[j][0]])
    {
        ll[e[j][0]]=a[e[j][0]]-e[j][1]+ll[u];
        mm[e[j][0]]=lo(mm[u],0)+(a[e[j][0]]-e[j][1]);
        ll2[e[j][0]]=ll2[u]+a[u]-e[j][1];
        mm2[e[j][0]]=lo(mm2[u],ll2[e[j][0]]);
        dfs2(e[j][0],u);
    }
    cc[co++]=ll[u];
    cc[co++]=mm2[u];
}

void dfs3(int u,int p,int k)
{
    if(mm[u]>=0)
    {
        _u(lb(ll[u]),k);
        if(k==1)++z;
    }
    for(int j=h[u];j;j=e[j][2])if(e[j][0]-p&&!ded[e[j][0]])dfs3(e[j][0],u,k);
}

void dfs4(int u,int p,int k)
{
    if(mm2[u]>=0)
    {
        z+=k;
        z+=_q(1);
    }
    else
    {
        z+=_q(lb(-mm2[u]));
    }
    for(int j=h[u];j;j=e[j][2])if(e[j][0]-p&&!ded[e[j][0]])dfs4(e[j][0],u,k);
}

void decomp(int u)
{
    dfs(u,-1);
    u=cen(u,-1,sz[u]);
    ded[u]=1;

    co=ll[u]=mm[u]=ll2[u]=mm2[u]=0;
    dfs2(u,-1);
    sort(cc,0,co);

    for(int j=h[u];j;j=e[j][2])if(!ded[e[j][0]])
    {
        dfs4(e[j][0],u,1), dfs3(e[j][0],u,1);
    }

    for(int j=h[u];j;j=e[j][2])if(!ded[e[j][0]])
    {
        dfs3(e[j][0],u,-1), dfs4(e[j][0],u,0);
    }

    for(int j=h[u];j;j=e[j][2])if(!ded[e[j][0]])
        decomp(e[j][0]);
}

#define _assert(x) if(!(x)) __builtin_trap();

int main(){
    scanf("%d",&n);
    for(int i=1;i<=n;++i)scanf("%d",a+i);
    for(int i=1,u,v,w;i<n;++i)
        scanf("%d%d%d",&u,&v,&w),e[++ne][0]=v,e[ne][1]=w,e[ne][2]=h[u],h[u]=ne,e[++ne][0]=u,e[ne][1]=w,e[ne][2]=h[v],h[v]=ne;
    decomp(1);
    printf("%lld",z);
}

Compilation message (stderr)

transport.c: In function 'main':
transport.c:125:5: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  125 |     scanf("%d",&n);
      |     ^~~~~~~~~~~~~~
transport.c:126:26: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  126 |     for(int i=1;i<=n;++i)scanf("%d",a+i);
      |                          ^~~~~~~~~~~~~~~
transport.c:128:9: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
  128 |         scanf("%d%d%d",&u,&v,&w),e[++ne][0]=v,e[ne][1]=w,e[ne][2]=h[u],h[u]=ne,e[++ne][0]=u,e[ne][1]=w,e[ne][2]=h[v],h[v]=ne;
      |         ^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 13 / 13
• Subtask 3: 13 / 13
• Subtask 4: 13 / 13
• Subtask 5: 13 / 13
• Subtask 6: 13 / 13
• Subtask 7: 13 / 13
• Subtask 8: 13 / 13
• Subtask 9: 13 / 13
• Subtask 10: 13 / 13