[Codeforces] Educational Round 123 (Rated for Div. 2) C. Increase Subarray Sums

Educational Codeforces Round 123 (Rated for Div. 2) C. Increase Subarray Sums

  • Time : O(n^2)
  • Space : O(n)
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#include <bits/stdc++.h>

#pragma optimization_level 3
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("Ofast")//Comment optimisations for interactive problems (use endl)
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimization ("unroll-loops")

struct PairHash {inline std::size_t operator()(const std::pair<int,int> & v) const {return v.first*31+v.second;}};

#define MAX_N 1010
#define INF 987654321
#define EPS 1e-9
#define ll long long
#define pll pair<ll, ll>
#define vpll vector<pll>
#define vall3 vector<array<ll,3>>
#define all3 array<ll,3>
#define all5 array<ll,5>
#define vall5 vector<all5>
#define vll vector<ll>
#define vs vector<string>
#define usll unordered_set<ll>
#define uspll unordered_set<pll, PairHash>
#define vvs vector<vs>
#define vvll vector<vll>
#define all(a) begin(a), end(a)

using namespace std;

vll solve(vll& A, ll x) {
ll n = A.size();
vll psum(n + 1);
vll ma(n + 1, LLONG_MIN);
vll res(n + 1);
for(ll i = 0; i < n; i++) {
psum[i + 1] = psum[i] + A[i];
for(ll j = 0; j <= i; j++) {
ma[i-j+1] = max(ma[i-j+1], psum[i+1] - psum[j]);
}
}
for(ll i = 0; i <= n; i++) {
for(ll j = i; j <= n; j++) {
res[i] = max(res[i], ma[j] + i * x);
}
if(i) res[i] = max(res[i], res[i-1]);
}
return res;
}

int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
ll tc = 1;
cin>>tc;
for(ll i = 1; i <= tc; i++) {
ll n, x;
cin>>n>>x;
vll A(n);
for(ll j = 0; j < n; j++) cin>>A[j];
auto res = solve(A,x);
for(auto& r : res)cout<<r<<' ';cout<<endl;
}
return 0;
}
Author: Song Hayoung
Link: https://songhayoung.github.io/2022/06/11/PS/Codeforces/edu-div2-123-c/
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