#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define all(v) v.begin(), v.end()
struct node{
vector<pair<ll, ll>> adj = {};
vector<ll> binJmp;
vector<ll> binDp;
vector<ll> binSum;
bool isCyc = 0;
ll mxd = 0;
ll mxch = 0;
ll treeDp = 0;
ll vis = 0;
};
vector<node> v;
vector<vector<ll>> cycles;
ll precDfs(ll a, ll p){
v[a].vis = 1;
ll cyc = -1;
for (auto &i : v[a].adj) {
ll b = i.second;
if(!v[b].vis){
cyc = max(cyc, precDfs(b, a));
}
else if(v[b].vis && b != p && !v[b].isCyc){
cyc = b;
v[b].isCyc = 1;
cycles.back().push_back(b);
}
}
if(cyc == a) return -1;
else if(cyc != -1) {
v[a].isCyc = 1;
cycles.back().push_back(a);
}
return cyc;
}
pair<ll, ll> ddfs(ll a){
v[a].vis = 2;
ll mxd = 0;
ll mxch = a;
for (auto &i : v[a].adj) {
node b = v[i.second];
if(b.vis < 2 && !b.isCyc){
pair<ll, ll> nd = ddfs(i.second);
if(mxd < nd.first + i.first){
mxd = nd.first + i.first;
mxch = nd.second;
}
}
}
v[a].mxd = mxd;
v[a].mxch = mxch;
return {mxd, mxch};
}
ll tdpDfs(ll a){
v[a].vis = 3;
ll dp = 0;
for (auto &i : v[a].adj) {
node b = v[i.second];
if(b.vis < 3 && !(b.isCyc && v[a].isCyc)){
dp = max(tdpDfs(i.second) + i.first, dp);
}
}
return dp;
}
int main()
{
ll n; cin >> n;
v.resize(n);
for (ll i = 0; i < n; i++) {
ll a, l; cin >> a >> l; a--;
v[i].binDp.push_back(l);
v[i].binSum.push_back(l);
v[i].binJmp.push_back(a);
v[i].adj.push_back({l, a});
v[a].adj.push_back({l, i});
}
for (ll i = 0; i < n; i++) {
v[i].binJmp.resize(22);
v[i].binSum.resize(22);
v[i].binDp.resize(22);
if(!v[i].vis){
cycles.push_back({});
precDfs(i, -1);
}
}
for (ll i = 0; i < n; i++) {
if(v[i].vis < 2 && v[i].isCyc){
pair<ll, ll> ret = ddfs(i);
v[i].treeDp = tdpDfs(ret.second);
}
}
ll res = 0;
for (ll i = 0; i < cycles.size(); i++) {
for (ll j = 0; j < cycles[i].size(); j++) {
ll a = cycles[i][j];
v[a].binDp[0] += v[v[a].binJmp[0]].mxd;
}
for (ll k = 1; k < 22; k++) {
for (ll j = 0; j < cycles[i].size(); j++) {
ll a = cycles[i][j];
ll b = v[a].binJmp[k - 1];
v[a].binSum[k] = v[a].binSum[k - 1] + v[b].binSum[k - 1];
v[a].binJmp[k] = v[b].binJmp[k - 1];
ll x = v[a].binSum[k - 1] + v[b].mxd;
ll y = v[a].binSum[k - 1] + v[b].binDp[k - 1];
v[a].binDp[k] = max(v[a].binDp[k - 1], max(x, y));
}
}
ll cmx = 0;
ll mxJmp = cycles[i].size() - 1;
for (ll k = 0; k < cycles[i].size(); k++) {
ll dp = 0;
ll cur = cycles[i][k];
ll s = 0;
for (ll j = 21; j >= 0; j--) {
if(mxJmp & (1 << j)) {
dp = max(dp, max(s + v[cur].binDp[j], (s + v[cur].mxd) * (cur != cycles[i][k])));
cur = v[cur].binJmp[j];
s += v[cur].binSum[j];
}
}
cmx = max(cmx, dp + v[cycles[i][k]].mxd);
cmx = max(cmx, v[cycles[i][k]].treeDp);
}
res += cmx;
}
cout << res << endl;
}
Compilation message
islands.cpp: In function 'int main()':
islands.cpp:106:22: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::vector<long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
106 | for (ll i = 0; i < cycles.size(); i++) {
| ~~^~~~~~~~~~~~~~~
islands.cpp:107:26: 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]
107 | for (ll j = 0; j < cycles[i].size(); j++) {
| ~~^~~~~~~~~~~~~~~~~~
islands.cpp:112:30: 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]
112 | for (ll j = 0; j < cycles[i].size(); j++) {
| ~~^~~~~~~~~~~~~~~~~~
islands.cpp:124:26: 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]
124 | for (ll k = 0; k < cycles[i].size(); k++) {
| ~~^~~~~~~~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
1 ms |
344 KB |
Output is correct |
| 2 |
Incorrect |
1 ms |
600 KB |
Output isn't correct |
| 3 |
Incorrect |
1 ms |
604 KB |
Output isn't correct |
| 4 |
Incorrect |
1 ms |
344 KB |
Output isn't correct |
| 5 |
Correct |
0 ms |
348 KB |
Output is correct |
| 6 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 7 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
| 8 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 9 |
Incorrect |
0 ms |
344 KB |
Output isn't correct |
| 10 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
| 11 |
Correct |
1 ms |
348 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
2 ms |
1116 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
4 ms |
1884 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
29 ms |
13024 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
118 ms |
44016 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
217 ms |
131072 KB |
Execution killed with signal 9 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
285 ms |
131072 KB |
Execution killed with signal 9 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
38 ms |
131072 KB |
Execution killed with signal 9 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
30 ms |
131072 KB |
Execution killed with signal 9 |
| 2 |
Halted |
0 ms |
0 KB |
- |
