[bzoj4429] [NWERC2015] Math Elementary Math Elementary School

At first I thought it was 2-sat. Qaq

Membrane of the following: After discretization of each of the answers, the connection between each logarithm and the answer is to see if the maximum number of matches equals n

1#include <cstdio>2#include <iostream>3#include <cstring>4#include <algorithm>5 #definell Long Long6 using namespacestd;7 Const intmaxn=2523<<2;8 structZs1{ll v;intID;} A[MAXN];9ll B[MAXN];intcnt,n1;Ten structzs{ One     intToo,pre;BOOLflow; A}e[233333];intTOT,LAST[MAXN]; -  ShortDIS[MAXN]; - intDL[MAXN],X[MAXN],Y[MAXN]; the intI,j,k,n,m,s,t,ans; -   - intRA,FH;CharRx; -InlineintRead () { +Rx=getchar (), ra=0, fh=1; -      while((rx<'0'|| Rx>'9') &&rx!='-') rx=GetChar (); +     if(rx=='-') fh=-1, rx=GetChar (); A      while(rx>='0'&&rx<='9') ra*=Ten, ra+=rx- -, Rx=getchar ();returnTalfh; at } -InlineBOOLBFs () { -memset (DIS,0, (t+1) <<1); -     intL=0, r=1, i,now;dl[1]=s,dis[s]=1; -      while(l<r&&!Dis[t]) -          for(I=last[now=dl[++l]];i;i=e[i].pre)if(e[i].flow&&!Dis[e[i].too]) indis[e[i].too]=dis[now]+1, dl[++r]=E[i].too; - //for (i=1;i<=t;i++) printf ("0->%d%d\n", I,dis[i]); to     returnDis[t]; + } - intDfsintXintMX) { the     if(x==t)returnMX; *     intUsed=0IBOOLW; $      for(I=last[x];i;i=e[i].pre)if(e[i].flow&&dis[e[i].too]==dis[x]+1){Panax NotoginsengW=dfs (E[i].too,1);if(w) { -e[i].flow=0, e[i^1].flow=1, used+=W; the             if(USED==MX)returnused; +         } A     } thedis[x]=0;returnused; + } -InlinevoidInsertintAintb) {//printf ("%d-->%d\n", A, b); $e[++tot].too=b,e[tot].flow=1, e[tot].pre=last[a],last[a]=tot, $e[++tot].too=a,e[tot].flow=0, e[tot].pre=last[b],last[b]=tot; - } - BOOLCMP (ZS1 a,zs1 b) {returna.v<B.V;} the intMain () { -n=read ();Wuyi      for(i=1; i<=n;i++) theJ=x[i]=read (), k=y[i]=read (), -a[++n1].v=j+k,a[++n1].v=j-k,a[++n1].v=1ll*j*K, WuA[n1-2].id=a[n1-1].id=a[n1].id=i; -Sort (A +1, A +1+N1,CMP);intCnt=0; Abouttot=1; $      for(i=1; I<=n1;insert (a[i].id,cnt+n), i++) -         if(a[i].v!=a[i-1].v| | i==1) b[++cnt]=a[i].v; - //for (i=1;i<=n1;i++) printf ("%lld%d\n", a[i].v,a[i].id); -s=0, t=n+cnt+1; A      for(i=1; i<=n;i++) Insert (s,i); +      for(i=1; i<=cnt;i++) Insert (i+n,t); the      while(BFS ())) Ans+=dfs (S,1<< at); -     if(ans==N) { $          for(i=1; i<=n;i++) the              for(J=last[i];j;j=e[j].pre)if(e[j].too&&!E[j].flow) { thell k=b[e[j].too-n]; the                 if(x[i]+y[i]==k) printf ("%d +%d =%lld\n", x[i],y[i],k);Else the                 if(x[i]-y[i]==k) printf ("%d-%d =%lld\n", x[i],y[i],k);Else -                 if(1ll*x[i]*y[i]==k) printf ("%d *%d =%lld\n", x[i],y[i],k); in                  Break; the             } the}ElsePuts"Impossible"); About     return 0; the}

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[bzoj4429] [NWERC2015] Math Elementary Math Elementary School