Submission #1137450

#	Time	Username	Problem	Language	Result	Execution time	Memory
1137450		icoder178	Harbingers (CEOI09_harbingers)	C++17	90 / 100	108 ms	40260 KiB

harbingers

#include<iostream>
#include<algorithm>
using namespace std;
#define int long long
const int maxv = (int) 4e18;
const int maxn = 100005;
int dp[maxn];
signed n,dst[maxn],rmv[maxn],s[maxn],v[maxn],ncnt = 0,rcnt = 0,chcnt = 0,connl[maxn],connr[maxn];
pair<signed,int> nconn[maxn],rmvd[maxn],cht[maxn];
pair<signed,pair<signed,int> > conn[maxn*2];
pair<bool,signed> dstack[maxn*2];
inline void fdp(int pos) {
    int l = -5, r = chcnt+5;
    while(l+1 < r) {
        int mid = (l+r)/2;
        bool isDecr;
        if(mid < 0) isDecr = true;
        else if(mid >= chcnt-1) isDecr = false;
        else {
            int vl1 = cht[mid].second-(int) v[pos]*(int) cht[mid].first;
            int vl2 = cht[mid+1].second-(int) v[pos]*(int) cht[mid+1].first;
            isDecr = (vl2 < vl1);
        }
        if(isDecr == true) l = mid;
        else r = mid;
    }
    dp[pos] = cht[r].second-(int) v[pos]*(int) cht[r].first+(int) v[pos]*(int) dst[pos]+(int) s[pos];
}
inline void prmv(int pos) {
    int l = -5, r = chcnt+5;
    while(l+1 < r) {
        int mid = (l+r)/2;
        bool isV;
        if(mid < 0) isV = true;
        else if(mid >= (chcnt-1)) isV = false;
        else {
            __int128_t x1 = cht[mid].first;
            __int128_t y1 = cht[mid].second;
            __int128_t x2 = cht[mid+1].first;
            __int128_t y2 = cht[mid+1].second;
            __int128_t x3 = dst[pos];
            __int128_t y3 = dp[pos];
            __int128_t v1 = (y3-y2)*(x2-x1);
            __int128_t v2 = (y2-y1)*(x3-x2);
            isV = (v1 > v2);
        }
        if(isV) l = mid;
        else r = mid;
    }
    rmv[pos] = r+1;
}
inline pair<int,int> predfs(int pos, int prevP) {
    int ncl = ncnt;
    for(int i = connl[pos]; i < connr[pos]; i++) {
        int targP = conn[i].second.first;
        int newV = conn[i].second.second;
        if(targP != prevP) {
            dst[targP] = dst[pos]+newV;
            fdp(targP);
            prmv(targP);
            nconn[ncnt].first = rmv[targP];
            nconn[ncnt].second = targP;
            ncnt++;
        }
    }
    int ncr = ncnt;
    return make_pair(ncl,ncr);
}
inline void postdfs(int pos, int prevP, int rcl, int ncl, int ncr) {
    ncnt = ncl;
    int rcr = rcnt;
    for(int i = rcr-1; i >= rcl; i--) {
        cht[chcnt] = rmvd[i];
        chcnt++;
    }
    rcnt = rcl;
}
void dfs(int pos, int prevP) {
    pair<int,int> nvl = predfs(pos,prevP);
    sort(nconn+nvl.first,nconn+nvl.second);
    int rcl = rcnt;
    for(int i = nvl.second-1; i >= nvl.first; i--) {
        while(chcnt > nconn[i].first) {
            rmvd[rcnt] = cht[chcnt-1];
            rcnt++;
            chcnt--;
        }
        int targP = nconn[i].second;
        cht[chcnt].first = dst[targP];
        cht[chcnt].second = dp[targP];
        chcnt++;
        dfs(targP,pos);
        chcnt--;
    }
    postdfs(pos,prevP,rcl,nvl.first,nvl.second);
}
signed main () {
    scanf("%d",&n);
    for(int i = 0; i < n-1; i++) {
        int a,b,c;
        scanf("%d%d%lld",&conn[i*2].first,&conn[i*2].second.first,&conn[i*2].second.second);
        conn[i*2+1].first = conn[i*2].second.first;
        conn[i*2+1].second.first = conn[i*2].first;
        conn[i*2+1].second.second = conn[i*2].second.second;
    }
    sort(conn,conn+n*2-2);
    for(int i = 0; i < n*2-2; i++) {
        connr[conn[i].first] = i+1;
    }
    for(int i = n*2-3; i >= 0; i--) {
        connl[conn[i].first] = i;
    }
    for(int i = 2; i <= n; i++) {
        scanf("%d%d",&s[i],&v[i]);
    }
    chcnt++;
    dfs(1,-1);
    for(int i = 2; i <= n; i++) {
        printf("%lld ",dp[i]);
    }
    printf("\n");
    return 0;
}

Compilation message (stderr)

harbingers.cpp: In function 'int main()':
harbingers.cpp:98:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   98 |     scanf("%d",&n);
      |     ~~~~~^~~~~~~~~
harbingers.cpp:101:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  101 |         scanf("%d%d%lld",&conn[i*2].first,&conn[i*2].second.first,&conn[i*2].second.second);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
harbingers.cpp:114:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  114 |         scanf("%d%d",&s[i],&v[i]);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~

• Subtask 1: 90 / 100