Hdu 5615 Jam ' s math problem (cross multiply judgment)

D.

Jam has a math problem to ask you, he just learned to factorization for example,X^2+6x+5= (x+1) (x+5)It's like a shape.Ax^2+bx+c=pqx^2+ (QK+MP) x+km= (px+k) (qx+m)< Span class= "Mrel" >< Span class= "Mord mathit" >  But he's stupid, he only does 
                                                                                                     
                                                                                                      p,q,m,k p , q,m,k as a positive integer please help him and ask if you can break it down           
                                                                                                      

Test instructions is asking a one-dollar two-time equation can the decomposition of cross-multiplication?

S.

The official problem: The first question is relatively simple, can be said to be a simple simulation problem, we considera,b,c10^9 < Span class= "Mord" > ?? , so we decided to reduce the complexity of the time,

for each number, because it is positive, so we can handle it a lot easier, for example 32=2*16< Span class= "base textstyle uncramped" > 216

In this way, time becomesO(√? a??? Yes? b??? ), easy to solve the problem

Is the enumeration, I think so ...

At that time the feeling may time out, also thought the composite decomposition .... I didn't do it at the end. It's a lot of thought.

PS: If you know the following, then this problem is much easier ...

For a polynomial like ax²+bx+c, the Δ=B²-4AC can be used to determine whether it can use the cross decomposition method to decompose the form. When Δ is a full-squared number, the polynomial can be multiplied by a cross-range of integers.

C. Enumeration

#include <iostream>#include<stdio.h>#include<math.h>using namespacestd;inta,b,c;intp[20000],cnt1;//Pintk[20000],cnt2;//kBOOLf () {Cnt1=cnt2=0; intSqrt1= (int) sqrt (a);  for(intI=1; i<=sqrt1;++i) {        if(a%i==0) {P[cnt1++]=i; P[cnt1++]=a/i; }    }    intSqrt2= (int) sqrt (c);  for(intI=1; i<=sqrt2;++i) {        if(c%i==0) {K[cnt2++]=i; K[cnt2++]=c/i; }    }    intq,m;  for(intI=0; i<cnt1;++i) {         for(intj=0; j<cnt2;++j) {Q=a/P[i]; M=c/K[j]; if(q*k[j]+m*p[i]==b) {                return true; }        }    }    return false;}intMain () {intT; scanf ("%d",&u);  while(t--) {scanf ("%d%d%d",&a,&b,&c); if(f ()) {printf ("yes\n"); }        Else{printf ("no\n"); }    }    return 0;}

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C2. When δ is a full-squared number, the polynomial can be multiplied by a cross-range of integers.

#include <iostream>#include<stdio.h>#include<math.h>using namespacestd;intMain () {intT;    __int64 A,b,c;    __int64 k,m; scanf ("%d",&T);  while(t--) {scanf ("%i64d%i64d%i64d",&a,&b,&c); M=b*b-4*a*C; K=(__int64) sqrt (m); if(k*k==L) {printf ("yes\n"); }        Else{printf ("no\n"); }    }    return 0;}

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Hdu 5615 Jam ' s math problem (cross multiply judgment)