# |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
217671 |
2020-03-30T12:00:49 Z |
mhy908 |
Islands (IOI08_islands) |
C++14 |
|
1318 ms |
131072 KB |
#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define sortvec(x) sort(all(x))
#define compress(x) x.erase(unique(all(x)), x.end())
using namespace std;
typedef long long LL;
typedef pair<int, int> pii;
typedef pair<LL, LL> pll;
typedef pair<int, LL> pil;
typedef pair<LL, int> pli;
const LL llinf=1987654321987654321;
const int inf=2000000000;
int n;
vector<pil> link[1000010];
bool ch[1000010];
void chdfs(int num, int par1, int par2){
ch[num]=true;
for(auto i:link[num]){
if(i.F==par1||i.F==par2)continue;
chdfs(i.F, num, par2);
}
}
LL ret, ans;
vector<int> cyc;
vector<LL> sum;
LL get_cyc(int num, int par){
if(ch[num]){
cyc.pb(num);
sum.pb(0);
return 0;
}
ch[num]=true;
int t=0;
for(auto i:link[num]){
if(i.F==par&&!t){
t++;
continue;
}
LL temp=get_cyc(i.F, num)+i.S;
if(temp>=0){
cyc.pb(num);
sum.pb(temp);
if(cyc[0]==num)return -llinf;
return temp;
}
}
return -llinf;
}
LL get_maxd(int num, int par1, int par2){
LL ret2=0;
for(auto i:link[num]){
if(i.F==par1||i.F==par2)continue;
LL temp=get_maxd(i.F, num, num)+i.S;
ret=max(ret, ret2+temp);
ret2=max(ret2, temp);
}
return ret2;
}
LL solve(int num){
cyc.clear(); sum.clear();
ret=0;
get_cyc(num, 0);
chdfs(cyc[0], 0, cyc[0]);
LL max1=llinf, max2=-llinf, dia=sum.back();
cyc.pop_back();
sum.pop_back();
int sz=cyc.size();
for(int i=0; i<sz; i++){
LL tmp=get_maxd(cyc[i], cyc[(i+sz-1)%sz], cyc[(i+1)%sz]);
ret=max(ret, sum[i]+tmp-max1);
ret=max(ret, dia-sum[i]+tmp+max2);
max2=max(max2, sum[i]+tmp);
max1=min(max1, sum[i]-tmp);
}
return ret;
}
int main(){
scanf("%d", &n);
for(int i=1; i<=n; i++){
int a; LL b;
scanf("%d %lld", &a, &b);
link[i].pb(mp(a, b));
link[a].pb(mp(i, b));
}
for(int i=1; i<=n; i++){
if(ch[i])continue;
ans+=solve(i);
}
printf("%lld", ans);
}
Compilation message
islands.cpp: In function 'int main()':
islands.cpp:87:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &n);
~~~~~^~~~~~~~~~
islands.cpp:90:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %lld", &a, &b);
~~~~~^~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
23808 KB |
Output is correct |
2 |
Correct |
18 ms |
23808 KB |
Output is correct |
3 |
Correct |
18 ms |
23808 KB |
Output is correct |
4 |
Correct |
18 ms |
23808 KB |
Output is correct |
5 |
Correct |
18 ms |
23808 KB |
Output is correct |
6 |
Correct |
18 ms |
23808 KB |
Output is correct |
7 |
Correct |
19 ms |
23808 KB |
Output is correct |
8 |
Correct |
18 ms |
23808 KB |
Output is correct |
9 |
Correct |
18 ms |
23808 KB |
Output is correct |
10 |
Correct |
18 ms |
23808 KB |
Output is correct |
11 |
Correct |
18 ms |
23808 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
19 ms |
23936 KB |
Output is correct |
2 |
Correct |
19 ms |
23936 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
23936 KB |
Output is correct |
2 |
Correct |
20 ms |
24192 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
27 ms |
24832 KB |
Output is correct |
2 |
Correct |
38 ms |
27264 KB |
Output is correct |
3 |
Correct |
31 ms |
24960 KB |
Output is correct |
4 |
Correct |
24 ms |
24320 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
44 ms |
28536 KB |
Output is correct |
2 |
Correct |
60 ms |
30888 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
120 ms |
36216 KB |
Output is correct |
2 |
Correct |
123 ms |
41960 KB |
Output is correct |
3 |
Correct |
155 ms |
51856 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
198 ms |
46072 KB |
Output is correct |
2 |
Correct |
267 ms |
68968 KB |
Output is correct |
3 |
Correct |
279 ms |
76384 KB |
Output is correct |
4 |
Correct |
350 ms |
93960 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
401 ms |
71740 KB |
Output is correct |
2 |
Correct |
1025 ms |
131072 KB |
Output is correct |
3 |
Correct |
370 ms |
67320 KB |
Output is correct |
4 |
Correct |
503 ms |
105308 KB |
Output is correct |
5 |
Correct |
478 ms |
105820 KB |
Output is correct |
6 |
Correct |
1318 ms |
76196 KB |
Output is correct |
7 |
Runtime error |
477 ms |
131072 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
463 ms |
131072 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |