Codeforces 677e-vanya and Balloons

Test instructions: Bomb-like game, but the cross of the bomb trajectory are equal length (that is, 4 directions) (Can fry ten, X), and then the result is the ability to blast the maximum value of the product of each lattice.

Analysis: A glance down is DP, but there are involved in 8 directions, so it is necessary to DP8 a direction respectively. Each direction is a one-dimensional DP.
And the size of the comparison will use to log, because to compare the size of "2^k1 and 3^k2 (K1>K2)", is not directly considered unrealistic, so the use of log into---"K1*log (2) and K2*log (3)" Size comparison.

Spit Time: This code is really difficult to play acridine, debugging N long ..... (The heart is broken)

#include <bits/stdc++.h>using namespaceStd;typedefLong LongLL;Const intMOD = 1e9 +7;Const intMAXN = ++Ten;structnode{intn1,n2,n3,l; Node () {N1=n2=n3=l=0;} Node (Charc) {N1=n2=n3=l=0; if(c=='1') n1=l=1; Else if(c=='2') n2=l=1; Else if(c=='3') n3=l=1; } Nodeoperator+ (Node &a) {Node t; T.n1=N1+A.N1; T.N2=N2+A.N2; t.n3=n3+a.n3; returnT; } Nodeoperator-(Node &a) {Node t; T.n1=N1-A.N1; T.N2=N2-A.N2; t.n3=n3-a.n3; returnT; }};CharW[MAXN][MAXN]; Node dp[8][maxn][maxn], ans;intdy[8]={-1,-1,0,1,1,1,0,-1};intdx[8]={0,-1,-1,-1,0,1,1,1};intN; ll Quick_ (ll X,intN) {    if(x==0)return 0; LL ans=1;  while(n) {if(n&1) ans=ans*x%MOD; X=x*x%MOD; N>>=1; }    returnans;}voidPrin (Node No) {cout<<"N1:"<<no.n1<<"N2:"<<no.n2<<"N3:"<<no.n3<<Endl;}voidinit () {memset (W,'0',sizeof(w)); intI, J, Z, X, y; scanf ("%d", &N);  for(i=1; i<=n;++i) scanf ("%s", w[i]+1);  for(i=1; i<=n;++i) for(j=1; j<=n;++j) for(z=0;z<8; ++z) dp[z][i][j]=Node (W[i][j]); //DP8 each direction separately .     for(z=0;z<4;++z) for(i=1; i<=n;++i) for(j=1; j<=n;++j) {x=I+DX[Z]; y=j+Dy[z]; if(w[i][j]!='0') {Dp[z][i][j]=dp[z][i][j]+Dp[z][x][y]; DP[Z][I][J].L+=dp[z][x][y].l+1; }            }     for(z=4;z<6;++z) for(i=n;i>=1;--i) for(j=n;j>=1;--j) {x=I+DX[Z]; y=j+Dy[z]; if(w[i][j]!='0') {Dp[z][i][j]=dp[z][i][j]+Dp[z][x][y]; DP[Z][I][J].L+=dp[z][x][y].l+1; }            }     for(z=6;z<8;++z) for(i=n;i>=1;--i) for(j=1; j<=n;++j) {x=I+DX[Z]; y=j+Dy[z]; if(w[i][j]!='0') {Dp[z][i][j]=dp[z][i][j]+Dp[z][x][y]; DP[Z][I][J].L+=dp[z][x][y].l+1; }                    }}intMain () {DoubleTan1, Tan2, tan=0; intI, J, Z, Lnor, Lrot, X, y;    Init ();  for(i=1; i<=n;++i) for(j=1; j<=n;++j) {Node No, RO; Lrot=lnor=MAXN; //Normal             for(z=0;z<8; z+=2) Lnor=min (Lnor, DP[Z][I][J].L), no=no+Dp[z][i][j];  for(z=0;z<8; z+=2)            {                if(dp[z][i][j].l>Lnor) {x=i+dx[z]* (Lnor); y=j+dy[z]*(Lnor); No=no-Dp[z][x][y]; }            }            //Rotate             for(z=1;z<8; z+=2) Lrot=min (Lrot, DP[Z][I][J].L), ro=ro+Dp[z][i][j];  for(z=1;z<8; z+=2)            {                if(dp[z][i][j].l>Lrot) {x=i+dx[z]* (Lrot); y=j+dy[z]*(Lrot); Ro=ro-Dp[z][x][y]; }            }            //in the middle of the add more            if(w[i][j]=='1') ro.n1-=3, no.n1-=3; Else if(w[i][j]=='2') ro.n2-=3, no.n2-=3; Else if(w[i][j]=='3') ro.n3-=3, no.n3-=3;            Node T; Tan1=no.n2*log (2) +no.n3*log (3); Tan2=ro.n2*log (2) +ro.n3*log (3); if(Tan1>tan) ans=no,tan=Tan1; if(Tan2>tan) ans=ro,tan=tan2; if(Fabs (tan-0) <1e-9)            {                if(ans.n1==0&&no.n1!=0) ans=No; Else if(ans.n1==0&&ro.n1!=0) ans=ro; }} LL Res=quick_ (2, ans.n2) *quick_ (3, ans.n3)%MOD; if(ans.n2==0&&ans.n3==0&&ans.n1==0) res=0; cout<<res<<Endl;}

Codeforces 677e-vanya and Balloons