Submission #796832

#	Time	Username	Problem	Language	Result	Execution time	Memory
796832		alexander707070	Wiring (IOI17_wiring)	C++14	0 / 100	1074 ms	12772 KiB

wiring

#include<bits/stdc++.h>
#define MAXN 200007
using namespace std;

const long long inf=1e17;

int n,m,last[2],start;
pair<int,int> p[MAXN];
long long dp[MAXN];
int pref[MAXN][2];
long long sum[MAXN][2];
int pr[MAXN][2],nxt[MAXN][2];

long long cnt(int l,int r,int id){
    return pref[r][id]-pref[l-1][id];
}

long long getsum(int l,int r,int id){
    return sum[r][id]-sum[l-1][id];
}

long long cost(int l,int r){
    if(p[l].second==0 and p[r].second==1){
        if(cnt(l,r,0)<=cnt(l,r,1)){
            return  getsum(l,r,1) - ( getsum(l,r,0) + (cnt(l,r,1)-cnt(l,r,0))*p[pr[r][0]].first );
        }else{
            return  getsum(l,r,1) + (cnt(l,r,0)-cnt(l,r,1))*p[nxt[l][1]].first - getsum(l,r,0);
        }
    }else{
        if(cnt(l,r,0)<=cnt(l,r,1)){
            return getsum(l,r,0) + (cnt(l,r,1)-cnt(l,r,0))*p[nxt[l][0]].first - getsum(l,r,1);
        }else{
            return getsum(l,r,0) - ( (cnt(l,r,0)-cnt(l,r,1))*p[pr[r][1]].first + getsum(l,r,1) );
        }
    }
}

bool ok(int l,int r){
    if(p[l].second==p[r].second)return false;
    if(p[l].second==0){
        return nxt[l][1]-1==pr[r][0];
    }else{
        return nxt[l][0]-1==pr[r][1];
    }
}

void precalc(){
    for(int i=1;i<=n+m;i++){
        if(p[i].second==0){
            pref[i][0]++; sum[i][0]+=p[i].first;
        }else{
            pref[i][1]++; sum[i][1]+=p[i].first;
        }

        pref[i][0]+=pref[i-1][0];
        pref[i][1]+=pref[i-1][1];

        sum[i][0]+=sum[i-1][0];
        sum[i][1]+=sum[i-1][1];
    }

    last[0]=last[1]=0;
    for(int i=1;i<=n+m;i++){
        pr[i][0]=last[0]; pr[i][1]=last[1];

        if(p[i].second==0)last[0]=i;
        else last[1]=i;
    }

    last[0]=last[1]=n+m+1;
    for(int i=n+m;i>=1;i--){
        nxt[i][0]=last[0]; nxt[i][1]=last[1];
        
        if(p[i].second==0)last[0]=i;
        else last[1]=i;
    }
}

long long min_total_length(vector<int> r,vector<int> b){
    n=int(r.size()); m=int(b.size());
    for(int i=0;i<r.size();i++){
        p[i+1]={r[i],0};
    }
    for(int i=0;i<b.size();i++){
        p[r.size()+i+1]={b[i],1};
    }

    sort(p+1,p+n+m+1);
    precalc();

    for(int i=1;i<=n+m;i++){
        if(p[i].second==0)start=pr[i][1];
        else start=pr[i][0];

        dp[i]=inf;

        for(int f=start;f>=1;f--){
            if(!ok(f,i))break;
            if(cost(f,i)<0)cout<<1/0;
            dp[i]=min(dp[i],dp[f-1]+cost(f,i));
        }
    }

    return dp[n+m];
}

/*
int main(){
    cout<<min_total_length({1, 2, 3, 7}, {0, 4, 5, 9, 10})<<"\n";
}
*/

Compilation message (stderr)

wiring.cpp: In function 'long long int min_total_length(std::vector<int>, std::vector<int>)':
wiring.cpp:81:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   81 |     for(int i=0;i<r.size();i++){
      |                 ~^~~~~~~~~
wiring.cpp:84:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   84 |     for(int i=0;i<b.size();i++){
      |                 ~^~~~~~~~~
wiring.cpp:99:35: warning: division by zero [-Wdiv-by-zero]
   99 |             if(cost(f,i)<0)cout<<1/0;
      |                                  ~^~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 13
• Subtask 3: 0 / 10
• Subtask 4: 0 / 25
• Subtask 5: 0 / 45