Submission #1096052

#	Time	Username	Problem	Language	Result	Execution time	Memory
1096052		cpptowin	Tug of War (BOI15_tug)	C++17	0 / 100	81 ms	16732 KiB

tug

#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define maxn 600010
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define bitcount(x) __builtin_popcountll(x)
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1LL << j))
#define onbit(i, j) (i | (1LL << j))
#define vi vector<int>
#define all(x) x.begin(), x.end()
#define ss(x) (int)x.size()
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
void add(int &x, int k)
{
    x += k;
    x %= mod;
    if (x < 0)
        x += mod;
}
void del(int &x, int k)
{
    x -= k;
    x %= mod;
    if (x < 0)
        x += mod;
}
int cnt[maxn];
bool ok[maxn];
array<int, 3> edge[maxn];
int n, k;
vi ke[maxn];
bool used[maxn];
bool visedge[maxn];
vi things;
int total = 0;
int sum;
void dfs(int u,int val)
{
    for(int id : ke[u]) if(!visedge[id])
    {
        auto [i,j,w] = edge[id];
        int v = i + j - u;
        sum += w * val;
        visedge[id] = 1;
        dfs(v,-val);
        break;
    }
}
bitset<600010> f;
main()
{
#define name "TASK"
    if (fopen(name ".inp", "r"))
    {
        freopen(name ".inp", "r", stdin);
        freopen(name ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> k;
    fo(i, 1, 2 * n)
    {
        int u, v, w;
        cin >> u >> v >> w;
        edge[i] = {u, v + n, w};
        ke[u].pb(i);
        ke[v + n].pb(i);
        used[u] = 1;
        used[v + n] = 1;
        ok[i] = 1;
    }
    int d = 0;
    fo(i, 1, 2 * n) if (!used[i]) return cout << "NO", 0;
    // fo(i,1,2 * n) cout << ss(ke[i]) << ' ';en;
    fo(i, 1, 2 * n) if (ss(ke[i]) == 1)
    {
        // cout << i;en;
        ok[ke[i][0]] = 0;
        d += edge[ke[i][0]][2];
        ke[i].clear();
    }
    total += d;
    fo(i, 1, 2 * n) if (ok[i])
    {
        // cout << edge[i][0] << ' ' << edge[i][1] << ' ' << edge[i][2];en;
        ke[edge[i][0]].pb(i);
        ke[edge[i][1]].pb(i);
    }
    fo(i, 1, n) if (ss(ke[i]) and !visedge[ke[i][0]]) 
    {
        sum = 0;
        dfs(i,1);
        things.pb(abs(sum));
        total += sum;
    }
    f[0] = 1;
    // for(int it : things) cout << it << ' ';en;
    for (int it : things)
        f |= f << it;
    fo(i, 1, 600000) if (f[i] and abs(total - 2 * i) <= k) return cout << "YES",0;
    cout << "NO";
}

Compilation message (stderr)

tug.cpp:80:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   80 | main()
      | ^~~~
tug.cpp: In function 'int main()':
tug.cpp:85:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   85 |         freopen(name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
tug.cpp:86:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   86 |         freopen(name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 18
• Subtask 2: 0 / 30
• Subtask 3: 0 / 23
• Subtask 4: 0 / 29