#include"bits/stdc++.h"
using namespace std;
#define LL long long
#define REP(i, n) for(int (i)=0; (i)<(n); (i)++)
#define PB push_back
#define MP make_pair
#define MOD 1000000007
int N, M;
vector<pair<int, LL>> edge[300001];
int par[300001];
vector<pair<int, LL>> chi[300001];
vector<pair<int, int>> node;
LL a[300001] ={}, b[300001] ={};
void dfs(int now, int p){
for(int i=0; i<edge[now].size(); i++){
if(edge[now][i].first == p) continue;
chi[now].PB(MP(edge[now][i].first, edge[now][i].second));
par[edge[now][i].first] = now;
dfs(edge[now][i].first, now);
}
}
int d[300001] ={};
int depth(int now){
if(now == 0) return 0;
if(d[now] != 0) return d[now];
return d[now] = depth(par[now]) + 1;
}
LL my_binary_search(int now, LL ans, LL ok, LL ng){
while(abs(ok-ng) > 1){
LL m = (ok+ng) / 2;
LL tmp = 0;
for(int i=0; i<chi[now].size(); i++){
if(a[chi[now][i].first] > m) tmp += a[chi[now][i].first] - m;
else if(b[chi[now][i].first] < m) tmp += m - b[chi[now][i].first];
}
if(tmp == ans) ok = m;
else ng = m;
}
return ok;
}
LL func(int now, LL tmp){
LL ans = 0;
for(int i=0; i<chi[now].size(); i++){
if(a[chi[now][i].first] > tmp) ans += a[chi[now][i].first] - tmp;
else if(b[chi[now][i].first] < tmp) ans += tmp - b[chi[now][i].first];
}
return ans;
}
LL sanbun(int now){
/*LL l = 0;
LL r = 1000000000LL*300000LL;
//[l,r)
while(r-l > 1){
LL m = (l+r) / 2;
if(func(now, m-1) <= func(now, m)) r = m;
else l = m;
}
return l;*/
int m = INT_MAX;
int ans;
for(int i=0; i<2000; i++){
int tmp = func(now, i);
if(m > tmp){
m = tmp;
ans = i;
}
}
for(int i=0; i<2000; i++){
int tmp = func(now, i);
if(tmp == m) continue;
if(tmp == func(now, i+1)){
assert(false);
}
}
return ans;
}
int main(){
scanf("%d%d", &N, &M);
for(int i=0; i<N+M-1; i++){
int P;
LL C;
scanf("%d%lld", &P, &C);
P--;
edge[i+1].PB(MP(P, C));
edge[P].PB(MP(i+1, C));
}
par[0] = -1;
dfs(0, -1);
for(int i=0; i<N+M; i++){
node.PB(MP(depth(i), i));
}
sort(node.begin(), node.end());
reverse(node.begin(), node.end());
LL ans = 0;
for(int i=0; i<N+M; i++){
int now = node[i].second;
if(chi[now].size() == 0){
a[now] = 0;
b[now] = 0;
continue;
}
for(int j=0; j<chi[now].size(); j++){
a[chi[now][j].first] += chi[now][j].second;
b[chi[now][j].first] += chi[now][j].second;
}
LL tmp = sanbun(now);
LL nowAns = 0;
for(int j=0; j<chi[now].size(); j++){
if(tmp < a[chi[now][j].first]) nowAns += a[chi[now][j].first] - tmp;
else if(tmp > b[chi[now][j].first]) nowAns += tmp - b[chi[now][j].first];
}
ans += nowAns;
a[now] = my_binary_search(now, nowAns, tmp, -1);
b[now] = my_binary_search(now, nowAns, tmp, 1000000000LL*300000LL);
//cout << nowAns << " " << a[now] << " " << b[now] << endl;
}
cout << ans << endl;
}
Compilation message
fireworks.cpp: In function 'void dfs(int, int)':
fireworks.cpp:17:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0; i<edge[now].size(); i++){
~^~~~~~~~~~~~~~~~~
fireworks.cpp: In function 'long long int my_binary_search(int, long long int, long long int, long long int)':
fireworks.cpp:36:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0; i<chi[now].size(); i++){
~^~~~~~~~~~~~~~~~
fireworks.cpp: In function 'long long int func(int, long long int)':
fireworks.cpp:48:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0; i<chi[now].size(); i++){
~^~~~~~~~~~~~~~~~
fireworks.cpp: In function 'int main()':
fireworks.cpp:112:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j=0; j<chi[now].size(); j++){
~^~~~~~~~~~~~~~~~
fireworks.cpp:119:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j=0; j<chi[now].size(); j++){
~^~~~~~~~~~~~~~~~
fireworks.cpp:85:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &N, &M);
~~~~~^~~~~~~~~~~~~~~~
fireworks.cpp:89:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%lld", &P, &C);
~~~~~^~~~~~~~~~~~~~~~~~
fireworks.cpp: In function 'long long int sanbun(int)':
fireworks.cpp:81:9: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
return ans;
^~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
15 ms |
14464 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
15 ms |
14464 KB |
Output is correct |
| 2 |
Correct |
16 ms |
14464 KB |
Output is correct |
| 3 |
Incorrect |
15 ms |
14464 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
15 ms |
14464 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
15 ms |
14464 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
