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#include <stdio.h>

#define M 30
#define N 1000

/* Structures declaration */

struct ti {
    struct ti *p, *l, *r;
    char name[30];
    int phone;
};

/* Functions declaration */
int add (struct ti *root, char *name, int phone);
int del (struct ti *root, char name);
int find (struct ti *root, char name, int *phone);

struct ti*  new_item(char *name, int phone);


/* Implementation */
struct ti*  new_item(char *name, int phone) {
    struct ti *x = (struct ti*) malloc(sizeof(struct ti));
    x->p = x->l = x->r = NULL;
    strcpy(x->name, name);
    x->phone = phone;
    return x;
}

int add (struct ti *root, char *name, int phone) {
    int tmp;
    if(root == NULL) {
        fprintf(stderr, "Bad root\n");
        return 0;
    }

    tmp = strcmp(root->name, name);
    if(tmp > 0) {
        if(root->r == NULL) {
            struct ti *x = new_item(name, phone);
            root->r = x;
            x->p = root;
        } else {
            add(root->r, name, phone);
        }
    } else if(tmp < 0) {
        if(root->l == NULL) {
            struct ti *x = new_item(name, phone);
            root->l = x;
            x->p = root;
        } else {
            add(root->l, name, phone);
        }
    } else if(tmp == 0) {
        fprintf(stderr, "For name '%s' replace old phone '%d' with new phone '%d'",
                    name, root->phone, phone);
        root->phone = phone;
    }
    return 1;
}

/*
    Implement del and find and main
    ...
*/