#include <stdio.h>
char buff[100000000];
int len = 0;
int start_tag(int x)
{
        while(x >= 0 && buff[x] != '<'){
                //printf("%c",buff[x--]);
                x--;
        }
        return x;
}

int end_tag(int x)
{
        int open = 1;
        int close = 0;
        while(x < len) {
                if(buff[x] == '<') {
                        int check = 0;
                        while(x < len && buff[x] != '>') {
                                if(buff[x] == '<' && buff[x+1] == '/') {
                                        check = 1;
                                }
                                x++;
                        }
                        if(check) {
                                close++;
                        }else{
                                open++;
                        }
                        if(open == close) {
                                return (x);
                        }
                }
                x++;
        }
        printf("someting worng happend :( \n");
        while(1);
}

void del(int x, int y)
{
        printf("Filtered tag: ");
        for(; x <= y; x++) {
                printf("%c",buff[x]);
                buff[x] = ' ';
        }
        printf("\n");
}

void filter_tag(char str[],int len)
{
        int i = 0;
        while(i < len) {
                //printf("%d \n",i);
                if(buff[i] == str[0]) {
                        int j = i;
                        int k = 0;
                        int check = 0;
                        while(j < len && str[k] != '\0') {
                                if(str[k] != buff[j]) {
                                        check = 1;
                                        break;
                                }
                                j++;
                                k++;
                        }
                        if(!check) {
                                int start = start_tag(i);
                                int end = end_tag(j);
                                del(start,end);
                        }
                }
                i++;
        }
}

int main()
{
        FILE *f1,*f2;
        char str[1000];
        printf("search string\n");
        scanf("%s",str);
        f1 = fopen("index.html","r");
        f2 = fopen("index.htm","w");
        char c = getc(f1);

        while(c != EOF) {
                buff[len++] = c;
                c = getc(f1);
        }

        filter_tag(str,len);
        //printf("%s",buff);
        fprintf(f2,"%s",buff);

        fclose(f1);
        fclose(f2);
        return 0;
}