Submission #79416

#	Time	Username	Problem	Language	Result	Execution time	Memory
79416		duality	Mousetrap (CEOI17_mousetrap)	C++11	25 / 100	1270 ms	78988 KiB

mousetrap

#define DEBUG 0

#include <bits/stdc++.h>
using namespace std;

#if DEBUG
// basic debugging macros
int __i__,__j__;
#define printLine(l) for(__i__=0;__i__<l;__i__++){cout<<"-";}cout<<endl
#define printLine2(l,c) for(__i__=0;__i__<l;__i__++){cout<<c;}cout<<endl
#define printVar(n) cout<<#n<<": "<<n<<endl
#define printArr(a,l) cout<<#a<<": ";for(__i__=0;__i__<l;__i__++){cout<<a[__i__]<<" ";}cout<<endl
#define print2dArr(a,r,c) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<a[__i__][__j__]<<" ";}cout<<endl;}
#define print2dArr2(a,r,c,l) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<setw(l)<<setfill(' ')<<a[__i__][__j__]<<" ";}cout<<endl;}

// advanced debugging class
// debug 1,2,'A',"test";
class _Debug {
    public:
        template<typename T>
        _Debug& operator,(T val) {
            cout << val << endl;
            return *this;
        }
};
#define debug _Debug(),
#else
#define printLine(l)
#define printLine2(l,c)
#define printVar(n)
#define printArr(a,l)
#define print2dArr(a,r,c)
#define print2dArr2(a,r,c,l)
#define debug
#endif

// define
#define MAX_VAL 999999999
#define MAX_VAL_2 999999999999999999LL
#define EPS 1e-6
#define mp make_pair
#define pb push_back

// typedef
typedef unsigned int UI;
typedef long long int LLI;
typedef unsigned long long int ULLI;
typedef unsigned short int US;
typedef pair<int,int> pii;
typedef pair<LLI,LLI> plli;
typedef vector<int> vi;
typedef vector<LLI> vlli;
typedef vector<pii> vpii;
typedef vector<plli> vplli;

// ---------- END OF TEMPLATE ----------

vi adjList[1000000];
int dp[1000000];
int doDFS(int u,int p) {
    int i;
    vi x;
    for (i = 0; i < adjList[u].size(); i++) {
        int v = adjList[u][i];
        if (v != p) x.pb(doDFS(v,u));
    }
    if (x.size() < 2) dp[u] = x.size();
    else {
        nth_element(x.begin(),x.end()-2,x.end());
        dp[u] = x[x.size()-2]+x.size();
    }
    return dp[u];
}
int main() {
    int i;
    int n,t,m;
    int a,b;
    scanf("%d %d %d",&n,&t,&m),t--,m--;
    for (i = 1; i < n; i++) {
        scanf("%d %d",&a,&b);
        a--,b--;
        adjList[a].pb(b);
        adjList[b].pb(a);
    }
    doDFS(t,-1);
    printf("%d\n",dp[m]);

    return 0;
}

Compilation message (stderr)

mousetrap.cpp: In function 'int doDFS(int, int)':
mousetrap.cpp:63:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i = 0; i < adjList[u].size(); i++) {
                 ~~^~~~~~~~~~~~~~~~~~~
mousetrap.cpp: In function 'int main()':
mousetrap.cpp:78:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d %d",&n,&t,&m),t--,m--;
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
mousetrap.cpp:80:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d",&a,&b);
         ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 0 / 20
• Subtask 2: 25 / 25
• Subtask 3: 0 / 20
• Subtask 4: 0 / 35