Submission #305950

#	Time	Username	Problem	Language	Result	Execution time	Memory
305950		aZvezda	Biochips (IZhO12_biochips)	C++14	0 / 100	218 ms	401912 KiB

biochips

#include <bits/stdc++.h>
using namespace std;
//#pragma GCC optimize ("O3")
//#pragma GCC target ("sse4")
#define endl "\n"
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
template<class T, class T2> inline bool chkmax(T &x, const T2 &y) { return x < y ? x = y, 1 : 0; }
template<class T, class T2> inline bool chkmin(T &x, const T2 &y) { return x > y ? x = y, 1 : 0; }
const ll mod = 1e9 + 7;
template<class T> inline void fix(T &x) {if(x >= mod | x <= -mod) {x %= mod;} if(x < 0) {x += mod;}}
#define out(x) cout << __LINE__ << ": " << (#x) << " = " << (x) << endl

const ll MAX_N = 1e5 + 10;
const ll MAX_W = 510;
vector<ll> g[MAX_N];
ll in[MAX_N], out[MAX_N], arr[MAX_N];
ll tme = -1;
ll dp[MAX_N][MAX_W];

void dfs(ll x) {
    in[x] = tme; tme ++;
    for(auto it : g[x]) {
        dfs(it);
    }
    out[x] = tme;
}

bool cmp(ll a, ll b) {
    return in[a] < in[b];
}

signed main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    ll n, w;
    cin >> n >> w;
    vector<ll> ord;
    for(ll i = 1; i <= n; i ++) {
        ll p;
        cin >> p >> arr[i];
        g[p].push_back(i);
        ord.push_back(i);
    }
    dfs(0);
    sort(ord.begin(), ord.end(), cmp);
    for(ll i = 0; i < MAX_N; i ++) {fill_n(dp[i], MAX_W, -mod);}
    dp[0][0] = 0;
    for(ll i = 0; i < ord.size(); i ++) {
        for(ll j = 0; j < MAX_W; j ++) {
            chkmax(dp[i + 1][j], dp[i][j]);
            chkmax(dp[out[ord[i]]][j + 1], dp[i][j] + arr[ord[i]]);
        }
    }
    cout << dp[ord.size() - 1][w] << endl;
    return 0;
}

Compilation message (stderr)

biochips.cpp: In function 'int main()':
biochips.cpp:49:21: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |     for(ll i = 0; i < ord.size(); i ++) {
      |                   ~~^~~~~~~~~~~~
biochips.cpp:9:78: warning: iteration 509 invokes undefined behavior [-Waggressive-loop-optimizations]
    9 | template<class T, class T2> inline bool chkmax(T &x, const T2 &y) { return x < y ? x = y, 1 : 0; }
      |                                                                            ~~^~~
biochips.cpp:50:25: note: within this loop
   50 |         for(ll j = 0; j < MAX_W; j ++) {
      |                       ~~^~~~~~~

• Subtask 1: 0 / 100