OJ Board

Code: Select all

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

int sort_function( const void *a, const void *b);

void main()
{
	char z[10005][50];
	char ara[50], temp[50];
	int n, i, j, k, l, cs=0, len, flag;

	while(scanf("%d", &n)==1)
	{
		cs++;
		if(cs!=1) printf("\n");
		i = 0;
		while(1)
		{
			scanf("%s", temp);
			if(!strcmp(temp, "EndOfText")) break;
         len = strlen(temp);
			for(j=0, k=0; j < len; j++)
				if(isalnum(temp[j]))
					ara[k++] = tolower(temp[j]);
			ara[k] = 0;
			temp[j] = 0;
         if(!k) continue;
			strcpy(z[i], ara);
         i++;
		}
		z[i][0] = 0;
		k = i;

		qsort((void *)z, k, sizeof(char)*50, sort_function);

      flag = 0;
		for(i=0; i<k; )
      {
      	strcpy(temp, z[i]);
         for(j=i, l=0; !strcmp(z[j], z[j+1]);j++, l++);
         if(++l==n)
         {
         	printf("%s\n", z[i]);
            flag = 1;
         }
         i = ++j;
      }
      if(!flag) printf("There is no such word.\n");
	}
}

int sort_function( const void *a, const void *b)
{
   return( strcmp((char *)a,(char *)b) );
}

Code: Select all

A word is a sequence of letters. Words are separated by non-letters.

Code: Select all

[c]
#include<stdio.h>
#include<ctype.h>
#include<string.h>
#include<stdlib.h>

struct TREE{
	int count;
	char *alpha;
	struct TREE *left,*right;
};

int judgeanswer; /* judge if there is no answer */

void getstring(char*);
void inorder(struct TREE *node,int num);

int main()
{	
	char letter[200];
	int num;
	struct TREE *root,*ptr;
	int nl=0;

	while(scanf("%d",&num)!=EOF){
		judgeanswer=0;

		root=(struct TREE *)malloc(sizeof(struct TREE));
		root->left=root->right=NULL;
		getstring(letter);
		root->alpha=(char *)malloc(strlen(letter)+1);
		strcpy(root->alpha,letter);
		root->count=1;
		
		if(strcmp(letter,"endoftext")) {
			while(1){
				getstring(letter);
				if(!strcmp(letter,"endoftext")) break;
				
				ptr=root;			
				while(1){
					if(!strcmp(letter,ptr->alpha)){
						ptr->count++;							
						break;
					}
					else if(strcmp(letter,ptr->alpha)>0){
						if(ptr->right==NULL){								
							ptr->right=(struct TREE*)malloc(sizeof(struct TREE));
							ptr=ptr->right;
							ptr->left=ptr->right=NULL;
							ptr->alpha=(char *)malloc(strlen(letter)+1);								
							strcpy(ptr->alpha,letter);
							ptr->count=1;								
							break;
						}
						else
							ptr=ptr->right;					
					}
					else {
						if(ptr->left==NULL){
							ptr->left=(struct TREE*)malloc(sizeof(struct TREE));
							ptr=ptr->left;								
							ptr->left=ptr->right=NULL;
							ptr->alpha=(char *)malloc(strlen(letter)+1);
							strcpy(ptr->alpha,letter);
							ptr->count=1;								
							break;								
						}
						else
							ptr=ptr->left;						
					}/* end of else */
				}/* end of while(1) */				
			}/* end of while(1) */		
			inorder(root,num);
		}/* end of if(strcmp(letter,"endoftext")) */
		if(nl) printf("\n");
		else nl=1;
		if(!judgeanswer) printf("There is no such word.\n");
		
	}/* end of "while(scanf("%d",&num)!=EOF)" */
	return 0;
}

void getstring(char* letter){
	char ch;	
	int i=0,state=0;

	while((ch=getchar())!=EOF){
		if(isalpha(ch)) {
			ch=tolower(ch);
			letter[i++]=ch;
			state=1;
		}
		else if(state==1)
			break;
	}
	letter[i]='\0';	
}

void inorder(struct TREE *node,int num){
	if(node!=NULL){
		inorder(node->left,num);
		if(node->count==num) {
			printf("%s\n",node->alpha);	
			judgeanswer=1;
		}
		inorder(node->right,num);			
	}
}
[/c]

Code: Select all

if(nl) printf("\n"); 
else nl=1; 

Code: Select all

2
abcd abcd
EndOfText
2
abcd
EndOfText
2
abcd abcd
EndOfText
2
abcd
EndOfText

Code: Select all

abcd

There is no such word.

abcd

There is no such word.