第一篇：c語言程序設(shè)計課后習題答案 第7章

/*練習7-1*/ #include main(){ int a[10],n,sum=0,i;float ave;printf(“enter n:n”);scanf(“%d”,&n);printf(“enter %d ge zheng shu:n”,n);for(i=0;i

scanf(“%d”,&a[i]);

sum=sum+a[i];

} ave=1.0*sum/n;printf(“ave=%.2fn”,ave);}

/*練習7-2*/ #include main(){

int a[10],n,i;printf(“enter n:n”);scanf(“%d”,&n);printf(“enter %d ge zheng shu:n”,n);for(i=0;i

printf(“第%d個:n”,i+1);

scanf(“%d”,&a[i]);

printf(“倒序:n”);

while(a[i]!=0)

{

printf(“%d”,a[i]%10);

a[i]=a[i]/10;

}

printf(“n”);} } /*練習7-3*/ #include main(){

int a[5],x,i,k=0;printf(“enter 5 ge zheng shu:n”);for(i=0;i<5;i++)

scanf(“%d”,&a[i]);printf(“enter x:n”);scanf(“%d”,&x);

for(i=0;i<5;i++)

if(a[i]==x)

{

printf(“xia biao wei : %dn”,i);

k=1;

}

if(k==0)

printf(“Not Foundn”);}

/*練習7-4*/ #include main(){

int a[10],n,i,k=0,x,max;printf(“enter n:n”);scanf(“%d”,&n);printf(“enter %d ge zheng shu:n”,n);for(i=0;i

scanf(“%d”,&a[i]);max=a[0];for(i=1;i<=n-1;i++)

if(max

{

max=a[i];

k=i;

}

printf(“max=%d

xia biao=%d”,max,k);

x=a[n-1];

a[n-1]=a[k];

a[k]=x;

printf(“n”);

for(i=0;i

printf(“

%d

”,a[i]);

printf(“n”);}

/*練習7-11*/ #include main(){ char str[80];int i,j,count=0;printf(“輸入一個以回車符結(jié)束的字符串:n”);i=0;while((str[i]=getchar())!='n')

i++;str[i]='