# |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
217743 |
2020-03-30T15:16:29 Z |
mhy908 |
Islands (IOI08_islands) |
C++14 |
|
1067 ms |
131076 KB |
#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define F first
#define S second
using namespace std;
typedef long long LL;
typedef pair<int, int> pii;
const LL llinf=1987654321987654321;
int n;
LL ret, ans;
vector<pii> link[1000010];
int cyc[1000010], re;
LL sum[1000010];
bool ch[1000010];
LL get_cyc(int num, int par){
if(ch[num]){
cyc[re]=num;
sum[re++]=0;
return 0;
}
ch[num]=true;
for(pii i:link[num]){
if(i.F==par){
par=0;
continue;
}
LL temp=get_cyc(i.F, num)+i.S;
if(temp>=0){
ch[num]=false;
cyc[re]=num;
sum[re++]=temp;
if(cyc[0]==num)return -llinf;
return temp;
}
}
ch[num]=false;
return -llinf;
}
LL get_maxd(int num, int par1, int par2){
LL ret2=0;
ch[num]=true;
for(pii 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;
}
int main(){
scanf("%d", &n);
for(int i=1; i<=n; i++){
int a, b;
scanf("%d %d", &a, &b);
link[i].pb(mp(a, b));
link[a].pb(mp(i, b));
}
for(int j=1; j<=n; j++){
if(ch[j])continue;
re=0; ret=0;
get_cyc(j, 0);
LL max1=llinf, max2=-llinf, dia=sum[--re];
for(int i=0; i<re; i++){
LL tmp=get_maxd(cyc[i], cyc[(i+re-1)%re], cyc[(i+1)%re]);
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);
}
ans+=ret;
}
printf("%lld", ans);
}
Compilation message
islands.cpp: In function 'int main()':
islands.cpp:56:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &n);
~~~~~^~~~~~~~~~
islands.cpp:59:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &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 |
17 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 |
17 ms |
23808 KB |
Output is correct |
8 |
Correct |
18 ms |
23808 KB |
Output is correct |
9 |
Correct |
20 ms |
23808 KB |
Output is correct |
10 |
Correct |
18 ms |
23808 KB |
Output is correct |
11 |
Correct |
19 ms |
23808 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
23936 KB |
Output is correct |
2 |
Correct |
19 ms |
23808 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
23936 KB |
Output is correct |
2 |
Correct |
20 ms |
24064 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
25 ms |
24576 KB |
Output is correct |
2 |
Correct |
40 ms |
26360 KB |
Output is correct |
3 |
Correct |
28 ms |
24576 KB |
Output is correct |
4 |
Correct |
23 ms |
24192 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
41 ms |
27256 KB |
Output is correct |
2 |
Correct |
59 ms |
28792 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
101 ms |
32888 KB |
Output is correct |
2 |
Correct |
111 ms |
37240 KB |
Output is correct |
3 |
Correct |
133 ms |
44536 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
185 ms |
39672 KB |
Output is correct |
2 |
Correct |
221 ms |
58136 KB |
Output is correct |
3 |
Correct |
252 ms |
62840 KB |
Output is correct |
4 |
Correct |
308 ms |
77176 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
401 ms |
63976 KB |
Output is correct |
2 |
Correct |
821 ms |
99448 KB |
Output is correct |
3 |
Correct |
341 ms |
55288 KB |
Output is correct |
4 |
Correct |
450 ms |
84344 KB |
Output is correct |
5 |
Correct |
441 ms |
85112 KB |
Output is correct |
6 |
Correct |
1067 ms |
60112 KB |
Output is correct |
7 |
Correct |
489 ms |
106352 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
484 ms |
131076 KB |
Execution killed with signal 9 (could be triggered by violating memory limits) |
2 |
Halted |
0 ms |
0 KB |
- |