Submission #217745

# Submission time Handle Problem Language Result Execution time Memory
217745 2020-03-30T15:17:58 Z mhy908 Islands (IOI08_islands) C++14
9 / 100
764 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;
        }
        sum[re]=get_cyc(i.F, num)+i.S;
        if(sum[re]>=0){
            ch[num]=false;
            cyc[re++]=num;
            if(cyc[0]==num)return -llinf;
            return sum[re];
        }
    }
    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:55:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
islands.cpp:58:14: 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 19 ms 23808 KB Output is correct
2 Runtime error 110 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
3 Incorrect 18 ms 23808 KB Output isn't correct
4 Correct 18 ms 23808 KB Output is correct
5 Incorrect 18 ms 23808 KB Output isn't correct
6 Runtime error 82 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
7 Runtime error 80 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
8 Runtime error 84 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
9 Runtime error 81 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
10 Correct 18 ms 23680 KB Output is correct
11 Incorrect 20 ms 23932 KB Output isn't correct
# Verdict Execution time Memory Grader output
1 Incorrect 23 ms 23936 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 85 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 143 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 46 ms 27264 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 110 ms 33016 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 184 ms 39672 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 405 ms 63988 KB Output is correct
2 Incorrect 764 ms 99448 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 480 ms 131076 KB Execution killed with signal 9 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -