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Submission #476245

# Submission time Handle Problem Language Result Execution time Memory
476245 2021-09-25T15:22:23 Z LptN21 Building Bridges (CEOI17_building) C++14
60 / 100
 100 ms 65644 KB 
#include <bits/stdc++.h>
using namespace std;
#define fastIO ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL)
#define PI acos(-1.0)
#define FF first
#define SS second
#define eps 1e-9
// vector
#define pb push_back
#define sz(v) int((v).size())
#define all(v) (v).begin(), (v).end()
#define lb lower_bound
#define ub upper_bound
// bit
#define CNTBIT(x) __builtin_popcount(x)
#define ODDBIT(x) __builtin_parity(x)
#define MASK(i) (1ll<<(i))
#define BIT(x, i) (((x)>>(i))&1)
#define SUBSET(big, small) (((big)&(small))==(small))
#define MINBIT(x) (x)&(-x)
// typedef
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> ii;
typedef pair<int, ii> i3;
/* CODE BELOW */
const int N=1e6+7, M=1e5+7;
const int MOD=1e9+7;
const ll oo=1e9+9;

int n, m, k, t;

int a[M], p[M];
ll _dp[M];

const ll _oo=1e16+9;

struct Line {
    ll m, b;
    Line() {m=oo;
        b=_oo;
    }
    Line(ll _m, ll _b) {
        m=_m, b=_b;
    }
    ll operator()(ll x) { return m * x + b; }
} st[N<<2];

void insert(int l, int r, Line seg, int o=0) {
  if(l + 1 == r) {
    if(seg(l) < st[o](l)) st[o] = seg;
    return;
  }
  int mid= (l + r) >> 1, lson = o * 2 + 1, rson = o * 2 + 2;
  if(st[o].m < seg.m) swap(st[o], seg);
  if(st[o](mid) > seg(mid)) {
    swap(st[o], seg);
    insert(l, mid, seg, lson);
  } else insert(mid, r, seg, rson);
}
ll query(int l, int r, int x, int o=0) {
  if(l + 1 == r) return st[o](x);
  int mid = (l + r) >> 1, lson = o * 2 + 1, rson = o * 2 + 2;
  if(x < mid) return min(st[o](x), query(l, mid, x, lson));
  else return min(st[o](x), query(mid, r, x, rson));
}

signed main() {
    //freopen("test.inp", "r", stdin);
    //freopen("test.out", "w", stdout);
    //fastIO;
    scanf("%d", &n);
    for(int i=1;i<=n;i++) scanf("%d", &a[i]);
    for(int i=1;i<=n;i++) {
        scanf("%d", &m);
        p[i]=p[i-1]+m;
    }

    _dp[1]=0;
    const int SUB1=1000;
    #define sqr(x) 1LL*(x)*(x)

    if(n<=SUB1) {
        for(int i=2;i<=n;i++) {
            _dp[i]=oo;
            for(int j=i-1;j>0;j--) {
                ll cost=sqr(a[i]-a[j])+p[i-1]-p[j];
                _dp[i]=min(_dp[i], _dp[j]+cost);
            }
        }
        printf("%lld", _dp[n]);
    } else {
        insert(1, N, {-2*a[1], sqr(a[1])-p[1]});
        for(int i=2;i<=n;i++) {
            _dp[i]=sqr(a[i])-(p[i]-p[i-1])+query(1, N, a[i]);
            insert(1, N, {-2*a[i], _dp[i]+sqr(a[i])});
            //printf("%d %lld %lld _ %lld\n", i, _dp[i], query(1, N, a[i]), _dp[i]+p[i]);
        }
        printf("%lld", _dp[n]+p[n]);
    }

    return 0;
}
/* stuff you should look for
    - int overflow, array bounds
    - special/edge cases (n=1?)
    - do smth instead of nothing and stay organized
    - WRITE STUFF DOWN
    - DONT JUST STICK ON ONE APPROACH
*/

Compilation message

building.cpp: In function 'int main()':
building.cpp:73:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
building.cpp:74:32: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |     for(int i=1;i<=n;i++) scanf("%d", &a[i]);
      |                           ~~~~~^~~~~~~~~~~~~
building.cpp:76:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |         scanf("%d", &m);
      |         ~~~~~^~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 27 ms 62788 KB Output is correct
2 Correct 30 ms 62812 KB Output is correct
3 Correct 26 ms 62836 KB Output is correct
4 Correct 29 ms 62936 KB Output is correct
5 Correct 28 ms 62908 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 74 ms 65288 KB Output is correct
2 Correct 79 ms 65476 KB Output is correct
3 Correct 74 ms 65476 KB Output is correct
4 Correct 72 ms 65352 KB Output is correct
5 Correct 70 ms 65348 KB Output is correct

Subtask #3
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 27 ms 62788 KB Output is correct
2 Correct 30 ms 62812 KB Output is correct
3 Correct 26 ms 62836 KB Output is correct
4 Correct 29 ms 62936 KB Output is correct
5 Correct 28 ms 62908 KB Output is correct
6 Correct 74 ms 65288 KB Output is correct
7 Correct 79 ms 65476 KB Output is correct
8 Correct 74 ms 65476 KB Output is correct
9 Correct 72 ms 65352 KB Output is correct
10 Correct 70 ms 65348 KB Output is correct
11 Correct 100 ms 65208 KB Output is correct
12 Correct 89 ms 65372 KB Output is correct
13 Correct 72 ms 65580 KB Output is correct
14 Correct 81 ms 65644 KB Output is correct
15 Correct 71 ms 65336 KB Output is correct
16 Correct 63 ms 65348 KB Output is correct
17 Incorrect 58 ms 65524 KB Output isn't correct
18 Halted 0 ms 0 KB -