1591 - Data Mining （UVA）

题目链接如下：

Online Judge

这道题我没完全看懂，搜了网上题解之后也是一知半解，没能理解为什么A和B只需要0～31之间枚举即可……

（抄袭）代码如下：

#include 
// #define debug
 
int pa, pb;
long long n, sp, sq, tmp, k;
 
int main(){
    #ifdef debug
    freopen("0.txt", "r", stdin);
    freopen("1.txt", "w", stdout);
    #endif
    while(scanf("%lld %lld %lld", &n, &sp, &sq) == 3){
        k = n * sq << 10;
        for(int a = 0; a < 32; ++a){
            for(int b = 0; b < 32; ++b){
                tmp = (n - 1) * sp;
                tmp = sq + ((tmp + (tmp << a)) >> b);
                if(tmp < k && tmp >= n * sq){
                    pa = a;
                    pb = b;
                    k = tmp;
                }
            }
        }
        printf("%lld %d %d\n", k, pa, pb);
    }
    #ifdef debug
    fclose(stdin);
    fclose(stdout);
    #endif
    return 0;
}