二级C语言课后练习题答案.pdf

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1、课后题答案：参考答案第一章【1-1.exe 1-2.c.obj.exe 1-3 顺序，分 枝（选择），循环第二章2-1 B 2-2 D 2-3 B 2-4 A 2-5 C 2-6 A 2-7 B 2-8 B2-9 A 2-10 C 2-11 B 2-12 B 2-13 A2-14 11,12 2-15 4.2,4.2【226 ,定义说明，执行语句2-1 7 关键字，用户标识符2-18 int,float,double2-19 float a=b=l;2-2 0 存贮单元2-21 3.52-22 a*b/c,a/c*b,b/c*a 2-2 3 把 10 赋予变量 s 2-24 bit,0/12-

2、25 8,127,01111111,-128,10000000（补码）2-26 32767,-32768,1111111111111111,1000000000000000 2-27 8,10,16【2-28-1（错误）#include stdio.h;main（）/*main function*/float r,s;/*/*r is radius*/,/*s is area of circular*/*/=5.0;s=3.14159*r*r;printf（%fn,s）【2-28-2（正确）#include stdio.h;main（）/*main function*/float r,s;/*

3、r is radius,s is area of circular*/r=5.0;s=3.14159*r*r;printf(n%fn,s);)12-29-1(错误)#include stdio.hmain/*main function*/float a,b,c,v;/*a,b,c are sides,v is volume of cube*/a=2.0;b=3.0;c=4.0v=a*b*c;printf(M%fn,v)【2-29-2(正确)#include main()/*main function*/float a,b,c,v;/*a,b,c are sides,v is volume of

4、 cube*/a=2.0;b=3.0;c=4.0;v=a*b*c;printf(M%fn,v);第三章3-1 C 3-2 C 3-3 D 3-4 C 3-5 D 3-6 B 3-7 C3-8 D 3-9 A 3-10 B 3-11 C 3-12 D 3-13 D3-14 C 3-15 C 3-16 C 3-17 C 3-18 A 3-19 C3-20 B 3-21(l)-200 2500(2)i=-200,j=2500(3)i=-200(换行)j=25003-22 12,0,0 3-2 3 一条语句,；【3-24】；3-25 100 25.81 1.89234,100/25.81/1.8923

5、4,100/25.81 1.892343-26 x=127,x=127,x=177,x=7f,x=1273-27 x=127,x=127,x=$127,x=$000127,x=%06d3-28 a=513.789215,a=513.79,a=513.78921500,a=513.78921500【3-29-11(错误)main(double a,b,c,s,v;printf(input a,b,c:n);scanf(%d%d%d,a,b,c);s=a*b;v=a*b*c;printf(%d%d%d,a,b,c);printf(s=%fn,s,v=%dn,v);)【3-29-2(正确)main(

6、)float a,b,c,s,v;printfCinput a,b,c:”)；scanf(%f%f%f:”,&a,&b,&c);s=a*b;v=a*b*c;printf(,a=%f,b=%f,c=%fn,a,b,c);printf(ns=%f,v=%fn,s,v);)3-30)main()int h,m;h=560/60;m=560%60;printf(%dh:%dm”,h,m);getch();)3-31main()int m,n;printf(input m&n:);scanf(%d%d,&m,&n);printf(,n%d,%dn,m/n,m%n);getch();)3-32main()

7、double x,y,z,s;printf(input x,y,z:)；scanf(%lf%lf%lfu,&x,&y,&z);s=(x+y+z)/3.0;printf(HnAverage=%6.1 lfn,s);getch();3-33main()int a,b,c,t;printf(Input a,b,c:)；scanf(%d%d%dH,&a,&b,&c);t=c;c=b;b=a;a=t;printf(,na,b,c=%d,%d,%dn,a,b,c);getch();)第四章4-1 A 4-2 A 4-3 A 4-4 D 4-5 C 4-6 A 4-7 B 4-8 A4-9 D 4-101

8、A 4-1 1 非零，零4-12,=,!=4-13!,&,ll 4-14!，关系运算符,&,ll 4-15!4-16(A)a=blla4 4-17 1 4-18 xmO)ll(ml=mO)&(dl=dO)age=yl-yO;else age=yl-yO-l;printf(nnThe studentV age is%du,age);getch();)14-23main()int m;printfCAninput a integer:);scanf(n%dn,&m);if(m%2=0)printf(n%d is event.,m);else printf(n%d is ord.n,m);getch

9、();)4-24main()int a,b,c,max;printf(Hninput a,b,c:);scanf(%d%d%d,&a,&b,&c);max=a;if(bmax)max=b;if(cmax)max=c;printf(nmax is%dn,max);getch();)4-25-1main()int x,y;printf(nninput x:);scanf(n%d,&x);if(x-5)&(x0)&(x-5)&(x10)if(x0)y=x+1;printf(Mnx is%d,y is%d,x,y);)else printf(ninput x is error!%cA007);getc

10、h();)(4-25-3main()int x,y;printf(nninput x:);scanf(%d,&x);if(x-5)&(x0)&(x10)y=x+l;printf(nx is%d,y is%d,x,y);getch();)4-25-4main()int x,y;printf(nninput x:);scanf(n%d,&x);switch(x)case-4:case-3:case-2:case-1:y=x;break;case 0:y=x-l;break;case 1 :case 2:case 3:case 4:case 5:case 6:case 7:case 8:case 9

11、:y=x+l;break;default:printf(Input x error!%c”,7);)printf(nnx is%d,y is%d,x,y);getch();第五章5-1 D 5-2 C 5-3 B 5-4 C 5-5 C 5-6 B 5-7 D 5-8 A5-9 D 5-10 D 5-11 5,4,6 5-1 2 死循环5-13-1 5-14 115-15 d=l,k+,k=0,xamin5-17main()int i,s=l,k=-l;for(i=l;i=50;i+)s=s+k*(2*i+l);k=-k;printf(ns=%dn,s);getch();)5-18-1main

12、()int i=l;double e=1.0,s=1.0;for(i=l;i=le-04)/*8 times*/s=s*i;i+；e=e+l/s;printf(,e=%10.6f,e);getch();5-19main()int y,k=O;for(y=1000;y=2000;y+)if(y%4=0&y%100!=0lly%400=0)printf(%1 Od,y);k+;if(k%3=0)printf(Hn);)getch();)5-20#include main()int i,j,n;printf(MInputn(l-10):H);do scanf(n%dn,&n);while(n10);

13、for(i=l;i=n;i+)for(j=l;j=40-i;j+)printf();for(j=l;j=2*i-l;j+)printf(*);printf(n);)for(i=n+1 ;i=2*n-l;i+)for(j=l;j=40-2*n+i;j+)printf();for(j=1 ;j=4*n-1 -2*i;j+)printf(*);printf(n);)getch();)第六章6-1 B 6-2 D 6-3 A 6-4 A 6-5 B 6-6 D 6-7 D 6-8 B6-9 A 6-10 A 6-11 C 6-12 26 6-13 1 6-14 ctype.h6-15 1 6-16 1

14、0A20B30C40D 6-17 7.29 101.298AB6-18 A7.29B 101.298 6-19 ABC6-20#include main()int k=0;char ch;while(ch=getchar()!=10)k+;printf(%4c%4d,ch,ch);if(k%3=0)printf(nn);)getch();6-21#include main()long k=0;char ch;while(ch=getchar()!=EOF)if(ch=0,&ch=,9)ch=ch-O;k=k*10+ch;)printf(n%ld,k);getch();6-22#include

15、main()int flag,k=O;char ch;while(ch=getchar()!=EOF)if(ch=10)k+;flag=O;else flag=l;)if(flag=l)k+;printf(n The line number is%dnu,k);getch();6-23#include main()int k=O;char ch;while(ch=getchar()!=10)if(ch=a,&ch=z)k+;printf(nn The lower letter number is%dnk);getch();6-24#include main()int i,j,n;printf(

16、Input line number:);scanf(%d,&n);for(i=l;i=n;i+)for(j=l;j=40-i;j+)printf();for(j=1;j=2*i-l;j+)printf(n%c,;64+i);printf(nn);)getch();)第七章7-1 C 7-2 C 7-3 B 7-4 C 7-5 A 7-6 D 7-7 A 7-8 127-9 9.000000 17-10 4 7-11 n=l,s 7-12=y,z*x 7-13 l,s*i,0,f(k)【7/4-1(错误)main()int m;printf(nInput a number:);scanf(n%d

17、,&m);m=fun(m);if(m=l)printf(HnThis number is a primer!n);elseprintf(nThis number is not a primer!n);getch();)fun(int n)int k,yes;for(k=2;k=n/2;k+)if(n%k=0)yes=0;else yes=l;return yes;)【714-2(正确)main()int m;printf(Input a number:);scanf(n%dn,&m);m=fun(m);if(m=l)printf(nnThis number is a primer!nH);el

18、seprintf(nnThis number is not a primer!n);getch();)fun(int n)int k,yes=l;for(k=2;k=n/2;k+)if(n%k=0)yes=0;return yes;7-15main()int a,b;printf(Input a&b:);scanf(%d%d,&a,&b);printf(,n%d%d=%d,a,b,mymod(a,b);getch();mymod(int a,int b)int z;z=a%b;return z;)7-16float fun(int n)return(1.0/n);main()int i,n,k

19、=l;float s=0.0;printf(Input n:n);scanf(,%d,&n);for(i=l;i=n;i+)s+=k*fun(i);k=-k;)printf(ns=%8,6f,s);getch();)7-17float f(int m)float t=1.0;int i;for(i=2;i=m;i+)t-=1.0/(i*i);return t;)main()int n;printfCInput n:H);scanf(d”,&n);printf(nt=%8.6fn,f(n);getch();)7-18#include float f(float x)float z;z=x*x-5

20、*x+4;return z;)main()float x,yl,y2,y3;printf(Input x:)；scanf(n%f&x);yi=f(2)；y2=f(x+15);y3=f(sin(x);printf(,yl=%10.4fnu,yl);printf(Hy2=%10.4fn,y2);printf(,y3=%10.4fn,y3);printf(n*END*)；getch();)第八章8-1 A 8-21 B 8-3 B 8-4 C 8-5 B 8-6 B 8-7 C 8-8 D8-9 B 8-10 C 8-11 C 8-12 C 8-13 110 8-14 7 18-15 char*p=

21、ch;,p=&ch;,scanf(%c”,p);,p=a;,printf(%c,p);8-16 s=p+3;,s-=2,50,*(s+l),2,10 20 30 40 508-17-1fun(x,y)int*x,*y;int zl,z2;zl=*x+*y;z2=*x-*y;*x=zl;*y=z2;)main()int*a,*b,A,B;a=&A,b=&B;printf(input two numbers:);scanf(M%d%dn,a,b);printf(a,b=%d,%dn”,*a,*b);printf(before call function:nn);printf(a=%d b=%dn”

22、,*a,*b);fun(a,b);printf(after call function:nH);printf(a=%d b=%dn,*a,*b);getch();)8-17-2fun(x,y)float*x,*y;float zl,z2;zl=*x+*y;z2=*x-*y;*x=zl;*y=z2;)main()float*a,*b,A,B；a=&A;b=&B;printf(input two real numbers:);scanf(f%fa,b);printf(na,b=%f,%fn”,*a,*b);printf(nbefore call function:n);printf(a=%f b=

23、%fnH,*a,*b);fun(a,b);printf(after call function:nu);printf(a=%f b=%fn,*a,*b);getch();)8-18fun(int*a,int*b,int*c)int max,min;max=*a;min=*a;if(*b*a)max=*b;if(*bmax)max=*c;if(*cmin)min=*c;*a=max;*c=min;)main()int a,b,c;printf(Input a,b,c:);scanf(n%d%d%d,&a,&b,&c);printf(Hbefore call function:nM);printf

24、(na=%d b=%d c=%dn,a,b,c);fun(&a,&b,&c);printf(”after call function:nH);printf(max=%d min=%dn,a,c);getch();)第 9 章9-1 D 9-2 A 9-3 A 9-4 A 9-5 C 9-6 A 9-7 B 9-8 D9-9 C 9-10 C 9-11 C 9-12 D 9-13 D 9-14 A,C(?)9-15 A 9-16 A 9-17 C 9-18 C 9-19 9,0 9-20 6 9-21 129-22 3 9-23 2721 9-24-850,2,0 9-25 k=p,(k)【9-

25、26 c=getchar(),c-659-27#include main()char*s,a100;int i,k=0,num10=0;s=a;printf(nInput an number string:);scanf(%sn,s);while(*s!=,O,)if(isdigit(*s)&(*s,0,)num*s-49+;if(*s=48)num9+;s+;)for(i=0;i%3dn,i+l,numi);printf(H 0-%3dn,num91);printf(”*TOTAL*”)；for(i=0;i=9;i+)k+=numi;printf(n%d”,k);getch();)9-28m

26、ove(int a10,int n)int i;for(i=n;i10;i+)ai-l=ai;a9=0;)main()int x10,i,n;printf(Minput 10 number:);for(i=0;i10;i+)scanf(n%d,&xil);printf(ninput the N:H);scanf(,%d,&n);move(x,n);printf(nAfter move tne member list is:n);for(i=0;i10;i+)printf(n%d H,xi);getch();)9-29main()int a100=0,b100=0,i,j;printf(nnln

27、put the number list(end with 32767):n u);for(i=0;i100;i+)scanf(%d,&ai);if(ai=32767)break;)i-；odd(a,b,i);printf(narray B:nu);for(i=0;i100;i+)if(bi!=0)printf(n%d n,bi);else break;getch();)odd(int a 100,int b 100,int n)int i,j=0;for(i=0;i=n;i+)if(ai%2!=0)bj+=ai；)9-30#include sort(char s,int n)int i,j,p

28、,t;for(j=0;j(n-l);j+)P=j；for(i=j+l;in;i+)if(sp=ai-l)i+;)while(ai-l!=32767);printf(nlnput inserted number:);scanf(n%d,&n);P=a；insert(p,n);p=a+1;printf(nOutput array a:nn);doif(*p!=32767)printf(n%d,*p+);while(*p!=32767);getch();)insert(int*q,int n)int*k;k=q；while(*q!=32767)q+;*(q+l)=*q;while(qk)if(n*(

29、q-l)*q=n;break;else q-;*(q+l)=*q;9-32main()int n,a16=0,*p;printf(nlnput an number:);scanf(%d,&n);p=a;change(a,n,p);printf(n=%dnn);while(p=a+15)printf(,%dH,*p+);change(x,n,p)int x16,n,*p;p=x+15;*p=0;if(n=O)return(O);while(n!=0)*p=n%2;P-；n/=2;)9-33#include main()int a15,*p,i;p=a;frandm(a);printf(nThe

30、array a is:);for(i=0;i15;i+)printf(H%d,*p+);frandm(a);int k=O,i,x,*q;for(i=0;i15;i+)ai=20;while(k15)x=rand()%20;for(i=0;i15;i+)if(ai=x)continue;else ak+=x;)9-34#define N 20main()intaNN,xN=0,yN=0,i,j,m,sum=0;printf(n Input N(20)scanf(n%d*,&m);printf(Hn Input array a%d%d:n,m,m);for(i=0;im;i+)for(j=0;j

31、m;j+4-)scanf(n%d;&aij);xi+=ai|j;yj+=ailj；if(i=j)sum+=aili;printf(nn After compute:n);for(i=0;im;i+)for(j=0；jm;j+)printf(%5d,aij);printf(M%5dnn,xi);for(i=0;im;i+)printf(H%5d,yi);printf(,nnSum=%dn,sum);getch();)19-35#define N 20main()int aNN,bNN,cNN,m,n,i,j;printf(n Input m,n(20)scanf(%d%d,&m,&n);prin

32、tf(n Input array A%d%d:nH,m,n);for(i=0;im;i+)for(j=0;jn;j+)scanfT%d”,&ai|jD;printf(nn Input array B%d%d:n,m,n);for(i=0;im;i+)for(j=0;jn;j+)scanf(%d,&bij);cirj=aij+bij;printf(n After compute array C:n);for(i=0;im;i+)for(j=O;jn;j+)printf(%5dn,cij)；printf(nn);)getch();)9-36main()int i,j,k;printf(Mn*A M

33、ULTIPLICATION TABLEprintfC”)；for(i=l;i10;i+)printf(,(%3d),i);printf(Mn-nn);for(i=l;i10;i+)for(j=0;j10;j+)if(j=O)printfCX%d)H,i);else printf(%5dprintf(nnM);)printf(n-nH);getch();)9-37#include stdio.h#include stdlib.hmain()static int m55=0,i,j;int k=0;printf(nBefore:n);for(i=0;i5;i+)for(j=0;j5;j+)mij=

34、rand()%100;printf(n%4d,mifj);if(+k)%5=0)printf(nH);printf(nnAfter:nH);for(i=0;i5;i+)for(j=0;ji;j+)k=mij;mij=mji;mji=k;k=0;for(i=0;i5;i+)for(j=0;j5;j+)printf(%4d;milj);if(+k)%5=0)printf(nH);printf(n Program end!n);)9-38#include stdio.hMmain()intm55=0,i,j;int k=0;printf(nBefore:n);for(i=0;i5;i+)for(j=

35、0;j5;j+)mij=rand()%100;printf(n%4d;mifjl);if(+k)%5=0)printf(nnn);printf(nAfler:n)；for(i=0;i5;i+)for(j=0;ji;j+)k=mij;mi|j=mji;mji=k;printf(%4d,mij)；if(+k)%5=0)printf(n);k=0;for(i=0;i5;i+)for(j=0;j5;j+)printf(%4d,mij);if(+k)%5=0)printf(n);printf(n Program end!n);getch();)第十章10-1 B 10-2 B 10-3 C 10-4 B

36、 10-5 A 10-6 A 10-7 C10-8 A 10-9 C 10-10?10-11 GFEDCB 10-12 XYZA10-13 SO 10-14 qwertyabcd 10-15 Itiss10-16 strlen(str),j-10-17 7 10-18 gotogood*10-10#include main()char strl=string,str28,*str3,*str4=string;strcpyCstrl/HELLOr,);strcpy(str2,HELLO2n);strcpy(str3；HELLO3);strcpy(str4,HELLO4);printf(%sn%s

37、n%sn%sn,strl,str2,str3,str4);getch();)*10-131main()char*p=BOOL”JOPK”JHKSP;int i;for(i=3;i=0;i,i)printf(%c,*pi);printf(n);getch();)10-19#include#include mygets(s)char*s;char ch;ch=getchar();while(ch!=10)*s=ch;s+;ch=getchar();*s=0;)myputs(s)char*s;int i,n;n=strlen(s);for(i=0;in;i+)putchar(*s+);)main()

38、char*str,s80;str=s;printf(Input a string:);mygets(str);printf(MnOutput the string:nu);myputs(str);printf(nnn);getch();)10-20#include main()char*str;str=(char*)malloc(1);printf(Input a string:nH);gets(str);if(fun(str)printf(HnThis is back-round-textn*);else printf(nnThis is not back-round-textnH);get

39、ch();)fun(char*s)int n,i,j,flag=l;n=strlen(s);for(i=O,j=n-l;ij;i+,j)if(*(s+i)!=*(s+j)flag=0;return(flag);)10-21#include#include char deltet(s,n)char*s;int n;char ch;if(nstrlen(s)printf(nnCANNOT DELETE IT!%cn,007);retum(V);else ch=*(s+n);do *(s+n)=*(s+n+l);n+;while(*(s+n-l)!=,O,);retum(ch);)main()cha

40、r str80,*p,ch;int n;printf(nlnput a string:n);p=str+l;gets(p);printf(MnDelete the nth character:);scanf(d”,&n);ch=deltet(str,n);printfCAnAfter delete the string:(ch=%c)n,ch);for(n=l;nstrlen(str);n+)putchar(*p+);getch();)第十一章11-1 D 11-2 B 11-3 D 11-4 C 11-5 IJKLEFGHABCD 11-6 711-7 8 11-8*(s+j),i+l,i

41、11-9 1711-10(*fun)(),(*fun)(a+i*h),mypoly11-11#include main(int argc,char*argv)char*str,*p;int i,k;str=(char*)malloc(50);printf(nlnput a text line(10 letters):n);scanf(s,str);p=argvl;k=strlen(str);if(argc=2)if(*p=t+,)for(i=0;i(*(p+1 )-*0);i+)printf(,%c,*(str+i);else if(*p=-*)for(i=k-*(p+1 )+O;i=k;i+

42、)printf(,%c,*(str+i);else for(i=k-10;ik;i+)printf(%c,*(str+i);getch();)11-12inti;ten_to_two(int a,int n)if(n=O)ai=O;else if(n=l)ai=l;else ai+=n%2;n=n/2;ten_to_two(a,n);)main()int a16=0;int n,k;i=0;en*or:printf(nnlnput an number:);scanf(n%dn,&n);if(n=0;k)printf(M%d,ak);getch();)11-13sumf(int m)if(m=l

43、)return(l);else retum(m+sumf(m-1);main()int n;printf(nInput n:)；scanf(n%d,&n);if(n0)printf(H%d,sumf(n);else printf(Input error!%c,7);getch();11-14long fib(int n)if(n=0lln=l)return(l);else return(fib(n-2)+fib(n-1);main()int n;printf(nnlnput n(=0)printf(H%ld,fib(n);else printf(nnlnput error!%c,7);getc

44、h();)第十二章12-1 B 12-2 B 12-3 A 12-4 C 12-5 D 12-61 B 12-7 A12-8 A 12-9 2,5,1,2,3,-2 12-10 2468第十三章13-1 B 13-2 C 13-3 B 13-4 C 13-5 D 13-6 A 13-7 D13-8 ar=9 ar=9 ar=ll 13-91 int*,*s,*b13-10#include#define MYALPHA(C)(isalpha(C)main()char ch;printf(nInput a character:);scanf(n%cH,&ch);if(MYALPHA(ch)prin

45、tf(nThis is a letter!);else printf(nnThis is not a letter!getch();13-11#define SWAP(t,x,y)(t)=(x);(x)=(y);(y)=(t);main()int x,y,t；printf(nnlnput x&yscanf(n%d%dn,&x,&y);SWAP(t,x,y)printf(nnx=%d y=%d,x,y);getch();)13-12main()int w,*px,*py,*pz;px=(int*)malloc(sizeof(int);py=(int*)malloc(sizeof(int);pz=

46、(int*)malloc(sizeof(int);printf(nlnput three numberscanf(%d%d%d,px,py,pz);if(*px*py)w=*px;*px=*py;*py二 w;if(*px*pz)w=*px;*px=*pz;*pz=w;if(*py*pz)w=*py;*py=*pz;*pz=w;printf(nnAfter exchange:);printf(M%d%d%d,*px,*py,*pz);getch();第十四章14-1 D 14-21 D 14-3 D 14-41 A 14-5 C 14-6 C 14-7 C14-8 B 14-9 struct

47、link*next;1 14-10 p-next,p-datax);printf(H%dn,(+p)-x);printf(%dn,+(*p-y);)14-12struct studchar num5,name10;int s4;float ave;)；typedef struct stud STU;STU readrec(a)STU a311;int i;for(i=0;i4;i+)a0.si=0;printf(Mn Input 30 students data:n);printf(M-num name si s2 s3 s4-nn);for(i=l;i5;i+)printf(u%d:H,i)

48、;scanf(,%s%s%d%d%d%d,ai.num,ai.name,&ai.sO,&ai.sl,ai.ave=(ai.s0+ai.sl+ai.s2+ai.s3)/4.0;a0.s0+=ai.s0;a0.sl+=ai.sl;a0.s2+=ai.s2;a0.s3+=ai.s3;printf(n);)a0.s0/=4;a0.sl/=4;a0.s2/=4;a0.s3/=4;)STU writerec(a)STU a31;int i;printf(nn Output 30 students data:nH);printf(n-num name si s2 s3 s4 ave-n);for(i=l;i

49、data;while(p-next!=O)if(p-datam)m=p-data;p=p-next;)printf(n*m=%d,m);return(m);)NODE*maxaddress(NODE*h)NODE*p,*q;int m;P=h；m=p-data;while(p-next!=O)if(p-datam)m=p-data;q=p;p=p-next;)printf(nn*madd=%ld,q);retum(q);)main()NODE*h,*s,*q;int maxnumber;printf(nnlnput some numbers(END WITH 0):nn);h=(NODE*)m

50、alloc(sizeof(NODE);q=h;scanf(%d,&maxnumber);while(maxnumber!=O)s=(NODE*)malloc(sizeof(NODE);s-data=maxnumber;q-next=s;q=s;scanf(n%d,&maxnumber);)q-next=W;printf(nMaxnumber is%d,max(h);printf(nMaxnumber Address is%ld,maxaddress(h);getch();)第十五章15-1 D 15-2 B 15-3 B 15-4 A 15-5 11110000 15-6 A&015-7 0I