UVa : 679 (Dropping Balls)



// http://uva.onlinejudge.org/external/6/679.html
// Runtime: 0.056s
// Tag: binary search 

// @BEGIN_OF_SOURCE_CODE

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <string>
#include <cctype>
#include <stack>
#include <queue>
#include <list>
#include <vector>
#include <map>
#include <sstream>
#include <cmath>
#include <bitset>
#include <utility>
#include <set>
#include <numeric>
#include <ctime>

#define Inf 2147483647
#define Pi acos(-1.0)
#define N 1000000
#define LL long long

inline LL Power(int b, int p) { LL ret = 1; for ( int i = 1; i <= p; i++ ) ret *= b; return ret; }

#define F(i, a, b) for( int i = (a); i < (b); i++ )
#define Fs(i, sz) for( size_t i = 0; i < sz.size (); i++ )
#define Fe(i, x) for(typeof (x.begin()) i = x.begin(); i != x.end (); i++)
#define Set(a, s) memset(a, s, sizeof (a))
#define max(a, b)  (a < b ? b : a)
#define min(a, b)  (a > b ? b : a)

using namespace std;

int lastNodeNum;

int searchNode (int at, int balls)
{
    int leftNode = 2 * at;
    int rightNode = leftNode + 1;

    if ( leftNode <= lastNodeNum && rightNode <= lastNodeNum ) {
        if ( balls % 2 ) return searchNode(leftNode, balls / 2 + 1);
        else return searchNode(rightNode, balls / 2);
    } else {
        return at;
    }

}

int main ()
{
    int testCases; scanf ("%d", &testCases);

    while ( testCases-- ) {
        int d, i; scanf ("%d %d", &d, &i);

        lastNodeNum = Power(2, d) - 1;

        printf ("%d\n", searchNode(1, i));
    }

    int minusOne; scanf ("%d", &minusOne);

	return 0;
}

// @END_OF_SOURCE_CODE

One thought on “UVa : 679 (Dropping Balls)

  1. Can You please tell what is wrong in this solution.

    #include
    #include
    #include
    using namespace std;
    int main()
    {
    int t, d ,n, k, lr,i; // lr is for left or right
    long int val;
    scanf(“%d”, &t);
    while(t–) {
    scanf(“%d%d”, &d, &n);
    k = n-1;
    val = 1;
    for (i = 0 ; i 0)
    k = (k/2) + (1 – lr);
    }
    cout << val<<"\n";
    }
    scanf("%d", &i); // minus 1
    return 0;
    }

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