常见的C语言面试编程题.doc

（1） 求n的阶乘，这是一个比较简单的题目，有很多方法，但用递归方法是最简单的了：#include #include int main() long factorial(long n); long n; scanf(%ld,&n); printf(%ld,factorial(n); return 0;long factorial(long d)/求阶乘 long m; if(d0) printf(d的阶乘不存在!); else if(d=0|d=1) m=1; else m=d*factorial(d-1); return m;（2）从一个文件读取整数，对其进行排序，然后再将排序的结果输入到原来文件当中，这是一个经常考的题目，即考你的文件操作，又考了排序，我在这里用的是选择排序#include #include int readtoarray(int *a,FILE *fp)/从文件里将整数读到数组里 int i=0; if(fp=NULL) exit(0); while(fgetc(fp)!=EOF) fscanf(fp,%d,&ai); printf(%dn,ai); i+; return i;void writetofile(int a,FILE *fp,int i)/将数组写到文件里去 int k = 0; if(fp=NULL) exit(0); while(ki) fprintf(fp,%c%d, ,ak+); void selectionSort(int *a,int i)/选择排序 int m,n; int tmp,min; for(m=0;m i-1;m+) min=m; for(n=m+1;n i;n+) if(anamin) min=n; tmp=am; am=amin; amin=tmp; int main() FILE* fp,* fpwrite; int i; int a10; fp=fopen(2.txt,r); i=readtoarray(a,fp); fclose(fp); selectionSort(a,i); fpwrite=fopen(2.txt,w); writetofile(a, fpwrite,i); fclose(fpwrite); return 0;1，单向链表的插入，删除，逆序操作#include #include typedef struct Node int key; struct Node* next;* node;node newNode(int k) node n=(node)malloc(sizeof(node); n-key=k; n-next=NULL; return n;void printlist(node n) if(!n) printf(n is NULL listn); while(n) printf(%d,n-key); printf( ); n=n-next; printf(n);node newList() int k; node head=(node)malloc(sizeof(node); scanf(%d,&k); if(k=0) head=NULL; return head; else node n=newNode(k); head=n; while(k) scanf(%d,&k); if(k!=0) node n1=newNode(k); n-next=n1; n=n-next; n-next=NULL; return head; node insertNode(node n,int p,int k) node n1=newNode(k); node head=(node)malloc(sizeof(node); head=n; if(head=NULL) n1-next=head; return n1; else if(p=1) n1-next=head; head=n1; return head; else int i=2; while(i!=p&(n-next) n=n-next; i+; if(n-next=NULL) printf(the p cant be foundn); return head; else n1-next=n-next; n-next=n1; return head; node deleteNode(node n,int k) node n1=(node)malloc(sizeof(node); node head=(node)malloc(sizeof(node); head=n; if(head=NULL) printf(list is NULLn); return head; else if(head-key=k) head=head-next; return head; while(n-key!=k&n-next) n1=n; n=n-next; if(n=NULL) printf(cant find the same value as k in this listn); return head; else n1-next=n-next; n=NULL; return head; node reverse(node n) node n110; node head=(node)malloc(sizeof(node); node n2=(node)malloc(sizeof(node); head=n; if(head=NULL) return head; else int i=0; while(head!=NULL) n2=head; head=head-next; n2-next=NULL; n1i=n2; i+; head=n1i-1; for(int j=i-1;j0;j-) n1j-next=n1j-1; return head; int main() node n=newList(); printlist(n); /插入操作 int k,p; scanf(%d,%d,&p,&k); node nn=insertNode(n,p,k); printlist(nn); /删除操作 int q; scanf(%d,&q); node nd=deleteNode(nn,q); printlist(nd); /链表的倒置操作 node m=reverse(n); printlist(m); return 0;2，双向链表的插入删除操作#include #include typedef struct Node int key; struct Node* pre; struct Node* next;* node;node newNode(int i) node n=(node)malloc(sizeof(node); n-key=i; n-pre=NULL; n-next=NULL; return n;node newduplinklist() int i; scanf(%d,&i); node n; if(i=0) n=NULL; return n; n=newNode(i); node head=n; int k=1; while(k!=0) scanf(%d,&k); if(k!=0) node n1=newNode(k); n-next=n1; n1-pre=n; n=n1; n-next=head; head-pre=n; return head;int sizeduplinklist(node n) if(n=NULL) return 0; node head=n; int i=1; while(head-next!=n) head=head-next; i+; return i;void print(node n) if(n=NULL) printf(此时链表为空!); else printf(输出链表:n); for(int i=0;ikey); n=n-next; printf(n); node insertNode(node n) int p,k; printf(插入位置p:n); scanf(%d,%d,&p,&k); printf(n); if(psizeduplinklist(n) printf(此位置超出链表的长度!n); return n; else if(ppre=n-pre; n-pre-next=m; m-next=n; n-pre=m; return m; else int i=1; while(i!=p) n1=n; n=n-next; i+; n1-next=m; m-pre=n1; m-next=n; n-pre=m; return head; node delNode(node n) int p; printf(删除位置p:n); scanf(%d,&p); printf(n); if(psizeduplinklist(n) printf(此位置超出链表的长度!n); return n; else if(pnext; n-pre-next=n-next; n-next-pre=n-pre; return head; else head=n; int i=1; while(i!=p) n1=n; n=n-next; i+; n1-next=n-next; n-next-pre=n1; return head; int main()node n=newduplinklist();printf(%dn,sizeduplinklist(n);print(n);node m=insertNode(n);print(m);node m1=delNode(m);print(m1);return 0;3，栈操作，用数组实现的包含出栈，入栈的操作#include #include typedef struct Sta int a20; int num;* sta;sta NullStack() sta s=(sta)malloc(sizeof(sta); s-num=0; return s;sta pushstack(sta s,int i) s-as-num=i; s-num=s-num+1; return s;sta popstack(sta s) if(s-num=0) printf(stack is NULLn); return s; s-num=s-num-1; return s;void printstack(sta s) if(s-num=0) printf(stack is NULLn); else for(int i=s-num-1; i=0;i-) printf(%dn,s-ai); int main()sta s=NullStack();s=pushstack(s,1);s=pushstack(s,2);printstack(s);s=popstack(s);s=popstack(s);printstack(s);return 0;4，队列操作，类似于栈，#include #include typedef struct Que int a20; int num;* que;que NullQueue() que q=(que)malloc(sizeof(que); q-num=0; return q;que enq(que q,int i) q-aq-num=i; q-num=q-num+1; return q;que deq(que q) if(q-num=0) printf(queue is NULLn); return q; for(int i=1;inum;i+) q-ai-1=q-ai; q-num=q-num-1; return q;voi