Submission #388461

#	Time	Username	Problem	Language	Result	Execution time	Memory
388461		cpp219	Split the sequence (APIO14_sequence)	C++14	71 / 100	554 ms	131076 KiB

sequence

#pragma GCC optimization "Ofast"
#pragma GCC optimization "unroll-loop"
#pragma GCC target ("avx2")

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define fs first
#define sc second
using namespace std;
const ll N = 1e5 + 6;
const ll lim = 3e5 + 6;
const ll inf = 1e9 + 7;
typedef pair<ll,ll> LL;

ll n,a[N],b[N],dp[N],k,best[211][N],val[N],pre[N];

ll sum(ll L,ll R){
    return b[R] - b[L - 1];
}

ll cal(ll x,ll y){
    return sum(1,x - 1) * sum(x,y);
}

void f(ll rm,ll L,ll R,ll lf,ll rg){
    if (L > R) return;
    ll chosen = 0,cur = (L + R)/2,mx = -inf;
    for (ll i = lf;i <= min(rg,cur);i++){
        if (rm - 1 >= i - 1) continue;
        ll now = pre[i - 1] + cal(i,cur);
        if (now > mx){
            mx = now; chosen = i;
        }
    }
    best[rm][cur] = chosen; val[cur] = mx;
    f(rm,L,cur - 1,lf,chosen); f(rm,cur + 1,R,chosen,rg);
}

void Trace(ll k,ll n){
    if (!k) return;
    ll p = best[k][n];
    cout<<p - 1<<" "; Trace(k - 1,p - 1);
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    #define task "60"
    if (fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        //freopen(task".out", "w", stdout);
    }
    cin>>n>>k;
    for (ll i = 1;i <= n;i++) cin>>a[i],b[i] = b[i - 1] + a[i];
    for (ll i = 1;i <= k;i++){
        f(i,1,n,1,n);
        for (ll j = i + 1;j <= n;j++) dp[j] = pre[j] = val[j];
    }
    cout<<dp[n]<<"\n"; Trace(k,n);

}

Compilation message (stderr)

sequence.cpp:1: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    1 | #pragma GCC optimization "Ofast"
      | 
sequence.cpp:2: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    2 | #pragma GCC optimization "unroll-loop"
      | 
sequence.cpp: In function 'int main()':
sequence.cpp:51:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   51 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 11 / 11
• Subtask 3: 11 / 11
• Subtask 4: 17 / 17
• Subtask 5: 21 / 21
• Subtask 6: 0 / 29