# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
294139 | ant101 | Tug of War (BOI15_tug) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <iostream>
#include <algorithm>
#include <cstring>
#include <iomanip>
#include <fstream>
#include <cmath>
#include <vector>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <map>
#include <stack>
#include <queue>
#include <assert.h>
#include <limits>
#include <cstdio>
#include <complex>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef double db;
typedef string str;
typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
#define mp make_pair
#define f first
#define s second
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<ld> vd;
typedef vector<str> vs;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<pd> vpd;
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend()
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define pf push_front
#define pb push_back
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)
const int MOD = 1e9+7; // 998244353; // = (119<<23)+1
const int MX = 4e3+5;
const ll INF = 1e18;
const ld PI = 4*atan((ld)1);
const int dx[4] = {0,1,0,-1}, dy[4] = {1,0,-1,0};
namespace io {
void setIn(string s) { freopen(s.c_str(),"r",stdin); }
void setOut(string s) { freopen(s.c_str(),"w",stdout); }
void setIO(string s = "") {
ios_base::sync_with_stdio(0); cin.tie(0); // fast I/O
// cin.exceptions(cin.failbit); // ex. throws exception when you try to read letter into int
if (sz(s)) {
setIn(s+".in");
setOut(s+".out");
} // for USACO
}
}
using namespace io;
namespace input {
template<class T> void re(complex<T>& x);
template<class T1, class T2> void re(pair<T1,T2>& p);
template<class T> void re(vector<T>& a);
template<class T, size_t SZ> void re(array<T,SZ>& a);
template<class T> void re(T& x) { cin >> x; }
void re(double& x) { string t; re(t); x = stod(t); }
void re(ld& x) { string t; re(t); x = stold(t); }
template<class Arg, class... Args> void re(Arg& first, Args&... rest) {
re(first); re(rest...);
}
template<class T> void re(complex<T>& x) { T a,b; re(a,b); x = cd(a,b); }
template<class T1, class T2> void re(pair<T1,T2>& p) { re(p.f,p.s); }
template<class T> void re(vector<T>& a) { F0R(i,sz(a)) re(a[i]); }
template<class T, size_t SZ> void re(array<T,SZ>& a) { F0R(i,SZ) re(a[i]); }
}
namespace output {
template<class T1, class T2> void pr(const pair<T1,T2>& x);
template<class T, size_t SZ> void pr(const array<T,SZ>& x);
template<class T> void pr(const vector<T>& x);
template<class T> void pr(const set<T>& x);
template<class T1, class T2> void pr(const map<T1,T2>& x);
template<class T> void pr(const T& x) { cout << x; }
template<class Arg, class... Args> void pr(const Arg& first, const Args&... rest) {
pr(first); pr(rest...);
}
template<class T1, class T2> void pr(const pair<T1,T2>& x) {
pr("{",x.f,", ",x.s,"}");
}
template<class T> void prContain(const T& x) {
pr("{");
bool fst = 1; for (const auto& a: x) pr(!fst?", ":"",a), fst = 0; // const needed for vector<bool>
pr("}");
}
template<class T, size_t SZ> void pr(const array<T,SZ>& x) { prContain(x); }
template<class T> void pr(const vector<T>& x) { prContain(x); }
template<class T> void pr(const set<T>& x) { prContain(x); }
template<class T1, class T2> void pr(const map<T1,T2>& x) { prContain(x); }
void ps() { pr("\n"); }
template<class Arg> void ps(const Arg& first) {
pr(first); ps(); // no space at end of line
}
template<class Arg, class... Args> void ps(const Arg& first, const Args&... rest) {
pr(first," "); ps(rest...); // print w/ spaces
}
}
using namespace output;
using namespace input;
ll add(ll a, ll b) {
a += b;
if(a >= MOD) {
a -= MOD;
}
return a;
}
ll sub(ll a, ll b) {
a -= b;
if(a < 0) {
a += MOD;
}
return a;
}
ll mul(ll a, ll b) {
return (a * b)%MOD;
}
void add_self(ll& a, ll b) {
a = add(a, b);
}
void sub_self(ll& a, ll b) {
a = sub(a, b);
}
void mul_self(ll& a, ll b) {
a = mul(a, b);
}
ll N, K;
pl buckets[MX];
set<ll> r1[MX];
set<ll> r2[MX];
pl pref[MX];
ll skill[MX];
pair<ll, ll> cr1[MX], cr2[MX];
ll vis[MX];
bitset<80010> dp;
ll ind = 0;
/*
ll lone = *(r1[i].begin());
r1[i].clear();
r2[pref[lone].s].erase(lone);
if (r2[pref[lone].s].size() == 1) {
<#statements#>
}
*/
int main() {
setIO();
re(N, K);
FOR (i, 1, 2*N+1) {
re(pref[i].f, pref[i].s, skill[i]);
r1[pref[i].f].insert(i);
r2[pref[i].s].insert(i);
}
FOR (i, 1, N+1) {
if (!sz(r1[i]) || !sz(r2[i])) {
ps("NO");
return 0;
}
}
queue<pl> q;
FOR (i, 1, N+1) {
if (sz(r1[i]) == 1) {
q.push({1, i});
}
if (sz(r2[i]) == 1) {
q.push({2, i});
}
}
ll currdiff = 0;
while (!q.empty()) {
pl todel = q.front();
q.pop();
if (todel.f == 1) {
ll lone = *(r1[todel.s].begin());
r1[todel.s].clear();
r2[pref[lone].s].erase(lone);
currdiff+=skill[lone];
if (r2[pref[lone].s].size() == 1) {
q.push({2, pref[lone].s});
}
} else {
ll lone = *(r2[todel.s].begin());
r2[todel.s].clear();
r1[pref[lone].f].erase(lone);
currdiff-=skill[lone];
if (r1[pref[lone].f].size() == 1) {
q.push({1, pref[lone].f});
}
}
}
FOR (i, 1, N+1) {
if (r1[i].size() == 2) {
cr1[i] = {*r1[i].begin(), *(--r1[i].end())};
}
if (r2[i].size() == 2) {
cr2[i] = {*r2[i].begin(), *(--r2[i].end())};
}
}
FOR (i, 1, N+1) {
if (!vis[i] && r1[i].size() == 2) {
ll diff1 = skill[cr1[i].f];
ll curr = cr1[i].s;
ll currarr = 1;
while (curr != cr1[i].f) {
if (currarr == 1) {
diff1-=skill[curr];
ll innd = pref[curr].s;
if (cr2[innd].f == curr) {
curr = cr2[innd].s;
} else {
curr = cr2[innd].f;
}
currarr = 2;
} else {
diff1+=skill[curr];
ll innd = pref[curr].f;
if (cr1[innd].f == curr) {
curr = cr1[innd].s;
} else {
curr = cr1[innd].f;
}
currarr = 1;
}
}
ll diff2 = skill[cr1[i].s];
curr = cr1[i].f;
currarr = 1;
while (curr != cr1[i].s) {
if (currarr == 1) {
diff2-=skill[curr];
ll innd = pref[curr].s;
if (cr2[innd].f == curr) {
curr = cr2[innd].s;
} else {
curr = cr2[innd].f;
}
vis[pref[curr].f] = true;
currarr = 2;
} else {
diff2+=skill[curr];
ll innd = pref[curr].f;
if (cr1[innd].f == curr) {
curr = cr1[innd].s;
} else {
curr = cr1[innd].f;
}
// vis[innd] = true;
currarr = 1;
}
}
vis[i] = true;
// cout << ind << " " << i << "\n";
buckets[ind++] = {diff1, diff2};
}
}
dp[currdiff+40000] = 1;
for (ll i = 0; i<ind; i++) {
// for (ll j = 0; j<80010; j++) {
// if (dp[0][j] != 1) {
// continue;
// }
// if (j+buckets[i].f < 0 || j+buckets[i].f > 80000) {
//
// } else {
// dp[1][j+buckets[i].f] = 1;
// }
// if (j+buckets[i].s < 0 || j+buckets[i].s > 80000) {
//
// } else {
// dp[1][j+buckets[i].s] = 1;
// }
// }
// for (ll j = 0; j<80010; j++) {
// dp[0][j] = dp[1][j];
// dp[1][j] = 0;
// }
bitset<80010> b1, b2;
if (buckets[i].f < 0) {
b1 = dp >> -buckets[i].f;
} else {
b1 = dp << buckets[i].f;
}
if (buckets[i].s < 0) {
b2 = dp >> -buckets[i].s;
} else {
b2 = dp << buckets[i].s;
}
dp = b1 | b2;
}
ll best = 1e13;
for (ll i = 0; i<80010; i++) {
if (!dp[i]) {
continue;
}
best = min(best, abs(i-40000));
}
if (best <= K) {
cout << "YES" << "\n";
} else {
cout << "NO" << "\n";
}
return 0;
}