面试题：十进制INT数字化为16进制字符串、实现字符串和数字的相互化

面试题：十进制INT数字化为16进制字符串、实现字符串和数字的相互化 自å??ç?ƒç?ƒäº†æ‰‹ï?Œå†?了ä??ä?ªç?‹åº?ï?š ç??ä??ä?ªï?šå??è?›åˆ?çš„æ•?å?—è??化ä?º16è?›åˆ? intmain(intargc,_TCHAR*argv[]) { inta=100000000,i=0,b; intc[8]={0}; printf( %10.4x ,a); while(a){ b=a-(a 4 4); c[i]=b; i++; a=a 4; } i=i-1; printf( Thenumberofhexis: ); for(intindex=i;index =0;index--) printf( %x ,c[index]); printf( ); return0; } ç??二ä?ªï?Œå?†ascIIå?—ç??è??化ä?ºå??è?›åˆ?æ•?å?—, ä??æ??æ•?å?—çš„è??化ï?• #include iostream #include stdio.h usingnamespacestd; intmain(){ char*str= asd ; constintN=strlen(str); int*array=newint[N-1]; inti=0; while(*str!='\0'){ array[i]=(int)(*str);//ç›?æ??è??化å??å‚?å ?å ? cout array[i] endl; i++; str++; } } 3ã??æ•?å?—çš„è??化ä?ºå,—ç??ä??ï?Œå?—ç??ä??è??ä?ºæ•?å?—ï?š #include stdio.h #include stdlib.h char*i_to_a(intvalue){ chartemp[30]; char*result; inti=0,j=0; while(value!=0){ temp[i]=value%10+48; value/=10; i++; } result=(char*)malloc(sizeof(char)*(i+1)); for(j=0;j i;j++){ result[j]=temp[i-1-j]; } result[j]='\0'; returnresult; } boola_to_i(char*a,int*num){ char*p=a; inti=0; *num=0; //checkthestring if((*p=='+')||(*p=='-')) i=1; while(*(p+i)!='\0'){ if(*(p+i) ='0' *(p+i) ='9'){ i++; } else{ printf( Illegall!\n ); return1; } } if(i==1){ printf( Illegall!\n ); return1; } //startconverting,herethestringisinarightformulation while(*p!='\0'){ if((*p=='+')||(*p=='-')){ p++; } else{ *num=*num*10+*p-'0'; p++; } } if(*a=='-'){ *num=-(*num); } else{ } return0; } intmain(){ inti=6553567; char*p=i_to_a(i); printf( %s\n ,p); free(p); intnum=0; if(!a_to_i( 0000 , num)) printf( num=%d\n ,num); return0; } 4 æ•?å?—çš„è??化ä?ºå,—ç??ä??ï?Œå?—ç??ä??è??ä?ºæ•?å?—(2)ï?š #include stdio.h #include stdlib.h #include string.h voidmyitoa_first(longlonga,char*p){ if(a==0) { *p='\0'; } else{ myitoa_first(a/10,p+1); *p=a%10+'0'; } } voidmyitoa_second(char*p){ char*p1=p; char*p2=p+strlen(p)-1; inta; while(p1 p2) { a=*p2; *p2=*p1; *p1=a; p1++; p2--; } } voidmyitoa(longlonga,char*p){ myitoa_first(a,p); myitoa_second(p); } intmyatoi(char*pp){ char*p=pp; intsum=0; boolflag=0; if(*p=='+') { flag=0; p++; } elseif(*p=='-') { flag=1; p++; } while(*p!='\0') { if(*p ='0' *p ='9') { sum=sum*10+*p-'0'; p++; } else break; } if(flag) { sum*=-1; } returnsum; } intmain(){ char*p=(char*)malloc(32*sizeof(char)); longlonga=12345; myitoa(a,p); printf(p); puts( ); char*pp= -1234567s89 ; intaa=myatoi(pp); printf( a=%d\n ,aa); }