hdu 4611 Balls Rearrangement

找规律，模拟，计算压缩;

最大公因数，最小公倍数

#include <iostream>#include <cstdio>#include <cmath>#include <cstring>#include <algorithm>using namespace std;typedef long long ll;/**    ∑abs(i%A - i%B) 0<=i<N*/ll getGCD ( ll a, ll b ){    for ( int t; b; )    {        t = a % b;        a = b;        b = t;    }    return a;}ll getLCM ( ll a, ll b ){    return a * b / getGCD ( a, b );}ll mabs ( ll a ){    return a > 0 ? a : -a;}ll solve ( ll lcm , ll a, ll b ){    ll res = 0;    ll lasta = 0, lastb = 0, last ;    ll numa = 0, numb = 0;    for ( last = 0; last < lcm; )    {        if ( lasta + a <= lastb + b )        {            lasta = min(a+lasta, lcm) ;            res += ( lasta - last ) * mabs ( numa - numb );            numa = 0;            numb = ( lasta - last + numb ) % b;            last = lasta;        }        else        {            lastb = min(b+lastb, lcm) ;            res += ( lastb - last ) * mabs ( numa - numb );            numb = 0;            numa = ( numa + lastb - last ) % a;            last = lastb;        }    }    return res;}int main(){#ifdef  __GNUC__    freopen ( "in.txt", "r", stdin );#endif // __GNUC__    int t;    ll n, a, b, lcm, res;    scanf ( "%d", &t );    while ( t-- )    {#ifdef  __GNUC__        scanf ( "%lld%lld%lld", &n, &a, &b );#else        scanf ( "%I64d%I64d%I64d", &n, &a, &b );#endif // __GNUC__        if ( a < b ) { swap ( a, b ); }        lcm = getLCM ( a, b );        res = solve ( lcm, a, b );        res = res * ( n / lcm );        lcm = n % lcm;        res += solve ( lcm, a, b );#ifdef  __GNUC__        printf("%lld\n", res);#else        printf("%I64d\n", res);#endif // __GNUC__    }    return 0;}