oj.uz

Submission #240067

# Submission time Handle Problem Language Result Execution time Memory
240067 2020-06-17T21:20:48 Z m3r8 Building Bridges (CEOI17_building) C++14
60 / 100
 140 ms 10616 KB 
#include <stdio.h>
#include <set>
#include <algorithm>

#define ll long long
#define INF 1e9
#define MINF -INF
#define N 100100

int flag;
ll w[N];
ll h[N];

struct line{
  ll m;
  ll b;
  double start;
  double end;
};
struct compare{
  bool operator()(line a, line b){
    if(!flag){
      if(a.m != b.m){
        return a.m > b.m;
      }else{
        if(a.b != b.b){
          return a.b > b.b;
        }else{
          return a.start < b.start;  
        };
      };
    }else{
      return a.start < b.start;  
    };
  };
};
double is(line a, line b){
  return ((double)(a.b - b.b))/((double)(b.m-a.m));  
};

std::set<line,compare> hull;

void insert(ll m, ll b, int i){
  flag = 0;
  //printf("%lld %lld\n",m,b);
  line tmp = {m,b,INF,0.0};  
  line perf = {m,b,INF,0.0};
  line perfp;
  line perfn;
  double f1,f2;
  int ttm=0;

  auto it = (hull.insert(tmp)).first;
  auto itn = it;
  auto itp = it;
  auto itpp =it;
  ++itn;
  if(itn != hull.end() && itp != hull.begin()){
    if(itn->m == tmp.m){
      hull.erase(tmp);  
      return;
    };
    double f1 = is(tmp,*itn);
    if(f1 <= itn->start){
      hull.erase(tmp);  
      return;
    };
  };
  if(itp != hull.begin()){
    itp--;
    while(itp != hull.begin()){
      itpp = itp;
      itp--;
      if(itpp->m == tmp.m)continue;
      f1 = is(tmp,*itpp);
      f2 = is(tmp,*itp);
      if(f1 > f2){
        ttm = 1;
        break;  
      };
    };
    if(ttm){
      itpp++;  
      itp++;
    };
    hull.erase(itpp,it);
    perf.start = is(tmp,*itp); 
    perfp = *itp;
    perfp.end = perf.start;
    hull.erase(itp);
    hull.insert(perfp);
  }else{
    perf.start = MINF;  
  };

  if(itn != hull.end()){
    itpp = itn;  
    itn++;
    while(itn != hull.end()){
      double f1 = is(*itn,*itpp);
      double f2 = is(tmp,*itn);
      if(f1 > f2)break;
      itpp = itn;
      itn++;
    };
    itn = it;
    itn++;
    hull.erase(itn,itpp);
    perf.end= is(tmp,*itpp);
    perfn = *itpp;
    perfn.start = perf.end;
    hull.erase(itpp);
    hull.insert(perfn);
  }else{
    perf.end = INF;
  };
  hull.erase(tmp);
  hull.insert(perf);
};

ll qry(ll x,int i){
  flag = 1;  
  line tmp = {0,0,(double)x,0};
  auto it = hull.lower_bound(tmp);
  it--;
  flag = 0;
  if(it->start <= x && it->end >= x){
    return it->m * x + it->b;  
  };
  //printf("Error\n");
  return -1;
};


int main(void){
  int n;
  scanf("%d",&n);
  for(int i = 0;i<n;i++){
    scanf("%lld",&h[i]);
  };
  for(int i = 0;i<n;i++){
    scanf("%lld",&w[i]);  
    if(i != 0){
      w[i] += w[i-1];  
    };
  };
  ll tmp = 0;
  insert(-2 * h[0],0 - w[0] + h[0] * h[0],0);
  for(int i = 1;i<n;i++){
    /*for(auto j: hull){
      printf("%d %lld %lld %f %f\n",i,j.m,j.b,j.start,j.end);  
    };
    */
    tmp = qry(h[i],i) + w[i-1] + h[i] * h[i];  
    /*
    dp[i] = INF;
    for(int j = 0;j<i;j++){
      dp[i] = std::min(dp[i],dp[j] + (h[i]-h[j]) * (h[i]-h[j]) + w[i-1] - w[j]);  
    };
    if(dp[i] != tmp){
      for(auto j: hull){
        printf("%d %lld %lld %f %f\n",i,j.m,j.b,j.start,j.end);  
      };
      printf("tmp: %lld %lld %d %lld %lld\n",tmp,dp[i],i,h[i],qry(h[i],i));
      break;
    };
    */
    insert(-2 * h[i],tmp - w[i] + h[i] * h[i],i);
  };
  printf("%lld\n",tmp);
  return 0;  
};

Compilation message

building.cpp: In function 'int main()':
building.cpp:137:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&n);
   ~~~~~^~~~~~~~~
building.cpp:139:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lld",&h[i]);
     ~~~~~^~~~~~~~~~~~~~
building.cpp:142:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lld",&w[i]);  
     ~~~~~^~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 256 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 5 ms 384 KB Output is correct
5 Correct 5 ms 384 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 127 ms 1920 KB Output is correct
2 Correct 126 ms 1984 KB Output is correct
3 Correct 128 ms 2016 KB Output is correct
4 Correct 128 ms 2012 KB Output is correct
5 Correct 110 ms 3448 KB Output is correct

Subtask #3
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 256 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 5 ms 384 KB Output is correct
5 Correct 5 ms 384 KB Output is correct
6 Correct 127 ms 1920 KB Output is correct
7 Correct 126 ms 1984 KB Output is correct
8 Correct 128 ms 2016 KB Output is correct
9 Correct 128 ms 2012 KB Output is correct
10 Correct 110 ms 3448 KB Output is correct
11 Correct 114 ms 3064 KB Output is correct
12 Correct 132 ms 2936 KB Output is correct
13 Correct 88 ms 2960 KB Output is correct
14 Correct 124 ms 3200 KB Output is correct
15 Correct 140 ms 10616 KB Output is correct
16 Correct 120 ms 4344 KB Output is correct
17 Correct 39 ms 2936 KB Output is correct
18 Incorrect 57 ms 3064 KB Output isn't correct