130 lines
2.8 KiB
C
130 lines
2.8 KiB
C
#include "dictionnary.c"
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#define FILE_SIZE 2030
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static Tree dictionnary;
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char is_small_letter(char c) {
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return ('a' <= c) && (c <= 'z');
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}
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char is_letter(char c) {
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return (('A' <= c) && (c <= 'Z')) || is_small_letter(c);
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}
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char to_upper(char c) {
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if ( is_small_letter(c) )
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return 'A' - 'a' + c;
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return c;
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}
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void upper_str(char *str) {
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while (*str) {
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*str=to_upper(*str);
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}
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}
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char contains_english(char *decoded, int length) {
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int i;
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char tmpword[FILE_SIZE];
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int maxwordlen=0;
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int len=0;
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int badlen=0;
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int w=0;
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int nb_english_word=0;
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for (i=0; i<length ; i++) {
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if ( is_letter(decoded[i]) ) {
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tmpword[w]=to_upper(decoded[i]);
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w++;
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} else {
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tmpword[w+1]='\0';
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if (w>5) {
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fprintf(stderr,"%s\n",tmpword);
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}
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if (is_element(dictionnary,tmpword)) {
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fprintf(stderr,"WORD: %s\n",tmpword);
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nb_english_word++;
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}
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w=0;
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}
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}
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return nb_english_word > 0;
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}
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void decode(char *src, char *decoded, int code[], int length) {
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int i,j;
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for (i=0,j=0;i<length;i++) {
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decoded[i]= ((src[i]) ^ (code[j]));
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j = (j+1)%3;
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}
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}
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int sum (char *str) {
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int res=0;
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while (str != '\0') {
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res += *str;
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}
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return res;
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}
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int main (int argc, char **argv) {
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FILE *fd=fopen("cipher1-line.txt","r");
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char src[FILE_SIZE],decoded[FILE_SIZE];
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char *w;
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char str[4];
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int code[3];
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int length;
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int i,j,k;
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fprintf(stderr,"Dictionnary creation\n");
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create_dico_from_file("words-line.txt");
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test("YOUTH");
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if (! fd) {
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fprintf(stderr,"Couldn't read cipher.enc");
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return 1;
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}
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i=0;
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while (fgets(str,4,fd)) {
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for (w=src; (*w != '\n') && (*w != '\0'); w++)
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;
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*w='\0';
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src[i]=atoi(str);
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i++;
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}
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src[i]='\0';
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length=i;
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fprintf(stderr,"length = %d\n",length);
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fclose(fd);
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// fprintf(stderr, "---\n");
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// for (i=0; i<length; i++) {
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// fprintf(stderr, "%c", src[i]);
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// }
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// fprintf(stderr,"\n---\n");
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decoded[length]='\0';
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char *tst_str="TatiBus";
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upper_str(tst_str);
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fprintf(stderr, "TatiBus => %s\n", tst_str);
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for (i='z'; i>='a'; i--) {
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fprintf(stderr,"\n%c: ", i);
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code[0]=i;
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for (j='a'; j<='z'; j++) {
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code[1]=j;
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for (k='a'; k<='z'; k++) {
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code[2]=k;
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decode(src,decoded,code,length);
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if (contains_english(decoded, length)) {
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printf("\ncode = %c,%c,%c", code[0],code[1],code[2]);
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printf("decoded message: %s",decoded);
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printf("Sum = ", sum(decoded));
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}
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}
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}
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}
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return 0;
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}
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