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

/// 0
/*void Prob1() {
    char rasp;

    printf("rasp = ");
    scanf("%c", &rasp);

    switch(rasp) {
        case 'a'
    }
}*/

/// 1
/// A
void EliminareLitera() {
    FILE *fin, *fout, *f;
    char lit;
    char text[100];
    int i, sfarsit;

    fin = fopen("f.in", "r");
    fout = fopen("f.out", "w");

    if(fin == NULL || fout == NULL)
        printf("Eroare deschidere fisier.");

    lit = fgetc(fin);
    fscanf(fin, "\n");
    //printf("%c\n", lit);

    while(fgets(text, 100, fin) != NULL) {
        printf("%s", text);
        for(i = 0; i < strlen(text); i++) {
            if(text[i] == lit) {
                strcpy(text + i, text + i + 1);
                i--;
            }
        }
        //printf("%s\n", text);
        fputs(text, fout);
    }
    fclose(fin);
    fclose(fout);
}

/// B
void EliminareLitera2() {
    FILE *fAppend, *fRead;
    char lit;
    char text[100];
    int i, sfarsit;

    fRead = fopen("f.in", "r");
    fAppend = fopen("f.in", "a");

    if(fAppend == NULL || fRead == NULL)
        printf("Eroare deschidere fisier.");

    fseek(fRead, 0, SEEK_END);
    sfarsit = ftell(fRead);
    //printf("%d", sfarsit);
    fseek(fRead, 0, SEEK_SET);

    lit = fgetc(fRead);
    fscanf(fRead, "\n");
    printf("%c\n", lit);

    while((fgets(text, 100, fRead) != NULL) && (ftell(fRead) <= sfarsit)) {
        printf("%s", text);
        for(i = 0; i < strlen(text); i++) {
            if(text[i] == lit) {
                strcpy(text + i, text + i + 1);
                i--;
            }
        }
        //printf("%s\n", text);
        fputs(text, fAppend);
    }
    fclose(fRead);
    fclose(fAppend);
}

/// 2
void InlocuireLitera() {
    FILE *f;
    char a, b;
    char text[100];
    int i, pos;

    f = fopen("f.in", "r+");

    if(f == NULL)
        printf("Eroare deschidere fisier.");

    a = fgetc(f);
    fgetc(f); /// spatiu
    b = fgetc(f);
    fscanf(f, "\n");
    printf("%c %c\n", a, b);

    char *p;
    pos = ftell(f);
    while(fgets(text, 100, f) != NULL) {
        printf("%s", text);

/*
        p = strchr(text, a);
        while(p = strchr(p, a) != NULL) {
            p[0] = b;
        }
*/

        for(i = 0; i < strlen(text); i++)
            if(text[i] == a)
                text[i] = b;

        printf("%s\n", text);

        fseek(f, pos, SEEK_SET);
        fputs(text, f);
        fflush(f);
        pos = ftell(f);
    }
    fclose(f);
}

/// 3
void ConvCase() {
    FILE *f;
    char text[100];
    int i, pos;

    f = fopen("f.in", "r+");

    if(f == NULL)
        printf("Eroare deschidere fisier.");

    pos = ftell(f);
    while(fgets(text, 100, f) != NULL) {
        printf("%s", text);

        for(i = 0; i < strlen(text); i++) {
            if(!(text[i] >= 'a' || text[i] <= 'z') &&
               !(text[i] >= 'A' || text[i] <= 'Z')) continue;
            if(text[i] >= 'a' && text[i] <= 'z')
                text[i] += 'A' - 'a';
            else text[i] -= 'A' - 'a';
        }

        printf("%s\n", text);

        fseek(f, pos, SEEK_SET);
        fputs(text, f);
        fflush(f);
        pos = ftell(f);
    }
    fclose(f);
}

/// 4
void AparitiiLitere() {
    FILE *f;
    char text[100];
    int i, j;
    int ap['z' - 'a' + 2] = {0};

    f = fopen("f.in", "r+");

    if(f == NULL)
        printf("Eroare deschidere fisier.");

    while(fgets(text, 100, f) != NULL) {
        for(i = 0; i < strlen(text); i++) {
            char c = text[i];
            if(!(text[i] >= 'a' || text[i] <= 'z') &&
               !(text[i] >= 'A' || text[i] <= 'Z')) continue;

            if(text[i] >= 'a' && text[i] <= 'z')
                ap[ text[i] - 'a' ]++;
            else ap[ text[i] - 'A' ]++;

        }

        for(j = 0; j <= 'z' - 'a'; j++) {
            printf("%c ", j+'a');
        }
        printf("\n");
        for(j = 0; j <= 'z' - 'a'; j++) {
            printf("%d ", ap[j]);
        }
        printf("\n\n");
    }

    int posMax = 0;
    for(j = 0; j <= 'z' - 'a'; j++) {
        if(ap[j] > ap[posMax])
            posMax = j;
    }
    for(j = 0; j <= 'z' - 'a'; j++) {
        if(ap[j] == ap[posMax])
            printf("%c ", j + 'a');
    }

    if(ap[posMax] == 0) printf("Nu exista litere");

    fclose(f);
    /*
    */
}

/// 5
void GasireCuvant() {
    FILE *f;
    char text[100], cuv[100], *p;
    int i, j;

    printf("Cuvant: ");
    scanf("%s", cuv);

    f = fopen("f.in", "r+");

    if(f == NULL)
        printf("Eroare deschidere fisier.");

    while(fgets(text, 100, f) != NULL) {
        p = text;
        while((p = strstr(p, cuv)) != NULL) {
            while(p[0] != ' ' && p != text) p--;
            if(p[0] == ' ') p++;

            while(p[0] != ' ' && p[0] != NULL){
                printf("%c", p[0]);
                p++;
            }
            printf("\n");
        }
    }

    fclose(f);
}

int main() {
    /*
    EliminareLitera();
    EliminareLitera2();
    InlocuireLitera();
    ConvCase();
    AparitiiLitere();
    */
    GasireCuvant();
    return 0;
}