rqnoj165 FBI序列

rqnoj165 FBI序列

#include < iostream >
using   namespace  std;

int  n;
int  f[ 2010 ];
int  b[ 2010 ];
int  c[ 2010 ];
char  s[ 2010 ];
int  main()
{
    gets(s);
    n = strlen(s);
    f[ 0 ] = b[ 0 ] = c[ 0 ] = 0 ;
     for ( int  i = 1 ;i <= n; ++ i){
        f[i] = f[i - 1 ];
        b[i] = b[i - 1 ];
        c[i] = c[i - 1 ];
         if (s[i - 1 ] == ' O ' )  continue ;
         if (s[i - 1 ] == ' F ' )
            f[i] ++ ;
         else   if (s[i - 1 ] == ' B ' )
            b[i] += f[i];
         else   if (s[i - 1 ] = ' I ' )
            c[i] += b[i];
    }
    printf( " %d\n " ,c[n]);
     return   0 ;
}