题目大意:一张图G,有一些障碍物,求路径长度一定(可环)时的路径总数
果断广搜
Program ttd; var n,m,t,i,j,k,x1,x2,y1,y2:longint; s:string; b:array[0..101,0..101] of boolean; f:array[0..15,0..101,0..101] of longint; begin readln(n,m,t); fillchar(b,sizeof(b),true); for i:=1 to n do begin readln(s); for j:=1 to m do if s[j]='*' then b[i,j]:=false; end; readln(x1,y1,x2,y2); fillchar(f,sizeof(f),0); f[0,x1,y1]:=1; for k:=1 to t do begin for i:=1 to n do for j:=1 to m do if f[k-1,i,j]>0 then begin if b[i+1,j] then inc(f[k,i+1,j],f[k-1,i,j]); if b[i-1,j] then inc(f[k,i-1,j],f[k-1,i,j]); if b[i,j+1] then inc(f[k,i,j+1],f[k-1,i,j]); if b[i,j-1] then inc(f[k,i,j-1],f[k-1,i,j]); end; end; { for k:=0 to t do begin for i:=1 to n do begin for j:=1 to m do begin write(f[k,i,j],' '); end; writeln; end; writeln; end; } writeln(f[t,x2,y2]); end.