Vijos P1496 match Stick equation "the second question of NOIP2008 raising group"

Title Link: https://vijos.org/p/1496

Main topic:

Give you n (n<24) A match stick, you can spell out how many shape like "a+b=c" equation? ("+" and "=" Each need two match sticks)

If A≠b, A+b=c and b+a=c are considered different equations (A, B, c>=0)

N sticks must all be used.

Topic Ideas:

In fact, the problem is very water, n maximum only 24, deducted + and = Only 20, direct enumeration on the line.

Just a little bit to know that each number will not exceed 1111.

Two-level for enumerates each number, judging whether the match is exhausted.

　

1 //2 //by Coolxxx3 //4#include <iostream>5#include <algorithm>6#include <string>7#include <iomanip>8#include <memory.h>9#include <time.h>Ten#include <stdio.h> One#include <stdlib.h> A#include <string.h> -#include <stdbool.h> -#include <math.h> the #defineMin (a) < (b) ( A):(B)) - #defineMax (a) (a) > (b)? ( A):(B)) - #defineABS (a) ((a) >0? ( A):(-(a))) - #defineLowbit (a) (a& (a)) + #defineSqr (a) (a) * (a) - #defineSwap (a) (a) ^= (b), (b) ^= (a), (a) ^= (b) + #defineEPS 1e-8 A #defineS 10000 at #defineMAX 2139062143 - #definePI 3.1415926535897 - #defineN 34 - #defineM 1111 - using namespacestd; - intN,m,cas,lll,ans; in inta[4]; - intr[Ten]={6,2,5,5,4,5,6,3,7,6}; to intCalintaa) + { -cas=0; the     if(aa==0)return 6; *      for(cas=0; aa;aa/=Ten) $cas+=r[aa%Ten];Panax Notoginseng     returnCAs; - } the voidWork () + { A     inti,j,x,y,z; the      for(i=0; i<m;i++) +     { -x=cal (i); $         if(x>=n-1)Continue; $Z=cal (i+i); -         if(x+x+z==N) -         { theans++; -             //printf ("%d+%d=%d\n", i,i,i+i);Wuyi         } the          for(j=i+1; j<=m;j++) -         { Wuy=Cal (j); -             if(x+y>=n-1)Continue; AboutZ=cal (i+j); $             if(x+y+z==N) -             { -ans+=2; -                 //printf ("%d+%d=%d\n", i,j,i+j); A             } +         } the     } - } $ intMain () the { the #ifndef Online_judge the //freopen ("1.txt", "R", stdin); the //freopen ("2.txt", "w", stdout); -     #endif in     inti,j,k; the //while (~scanf ("%s", s)) the      while(~SCANF ("%d", &n) &&N) About     { theans=0; then-=4; the Work (); +printf"%d\n", ans); -     } the     return 0;Bayi } the  the  - /* - // the  the // the */

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Vijos P1496 match Stick equation "the second question of NOIP2008 raising group"