[U]3.4.2 簡單的遞迴題

拷的POJ的代碼，直接A了。

/*ID:bysenLANG:C++PROG:heritage*/#include<iostream>#include<stdio.h>#include<string>#include<fstream>using namespace std;    ifstream fin("heritage.in"); ofstream fout("heritage.out"); int strlen( char *a ){ int i; for( i=0;a[i]!='\0';i++ )  ; return i; } void DG( char *a,char *b ){int left=0,right=strlen(a)-1;if( strlen(a)==1 ){fout<<a[0];return ;}    int left1,right1;    //left right1 left1 right    char root=a[0];    int index=0;left++;    while( b[index]!=root )index++;//通過中序遍曆找分劃點    right1=index;    left1=right1+1;if( left==right )fout<<a[right];else{char a1[100],b1[100];char a2[100],b2[100];int i;int flag=left;for( i=0;flag<=right1;flag++ )a1[i++]=a[flag];a1[i]='\0';for( i=0;i<index;i++ )b1[i]=b[i];b1[i]='\0';flag=left1;for( i=0;flag<=right;flag++ )a2[i++]=a[flag];a2[i]='\0';flag=index+1;for( i=0;flag<=right;flag++ )b2[i++]=b[flag];b2[i]='\0';if( left<=right1 )DG( a1,b1 );if( left1<=right )DG( a2,b2 );}    fout<<root;}    int main(){char dateP[100];char dateM[100];    fin>>dateM>>dateP;    DG( dateP,dateM );    fout<<endl;    return 0;}