Submission #217670

# Submission time Handle Problem Language Result Execution time Memory
217670 2020-03-30T11:57:22 Z mhy908 Islands (IOI08_islands) C++14
0 / 100
462 ms 131076 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];
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;
    }
    LL retnum=-llinf;
    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)retnum=temp;
        }
    }
    return retnum;
}

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);
    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:78:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
islands.cpp:81:14: 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 Runtime error 78 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
2 Runtime error 103 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
3 Runtime error 87 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
4 Incorrect 19 ms 23808 KB Output isn't correct
5 Runtime error 78 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
6 Runtime error 74 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
7 Runtime error 76 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
8 Runtime error 119 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
9 Runtime error 77 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
10 Incorrect 18 ms 23808 KB Output isn't correct
11 Incorrect 18 ms 23808 KB Output isn't correct
# Verdict Execution time Memory Grader output
1 Runtime error 94 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 84 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 222 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 138 ms 131072 KB Execution killed with signal 9 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 342 ms 131072 KB Execution killed with signal 9 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 214 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 393 ms 71740 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 462 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -