titouan
/
hackerrank
1
0
Fork 0
Code Issues 0 Pull Requests 0 Releases 0 Wiki Activity
Hackerrank solutions.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
39 Commits
1 Branch
56 KiB
 
 
 
 
Tree: bcddc575e2
Branches Tags
${ item.name }
Create branch ${ searchTerm }
from 'bcddc575e2'
${ noResults }
hackerrank/arithmetic_progressions/arithmetic_progressions.c

337 lines
7.6 KiB
Raw Blame History

// https://www.hackerrank.com/challenges/arithmetic-progressions
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "segtree.h"
#define INTS_START_SIZE 8
#define INTS_DELIM " \t\n"
#define BUF_SIZE 10000000
#define LINE_SIZE 16
#define BIG_MOD 1000003
/* Arithmetic modulo BIG_MOD */
long INVERSES[BIG_MOD];
void calc_inverses() {
long tmp[BIG_MOD - 2];
long acc = 2; // powers of 2 will run the full range of the set
int i;
for (i = 0; i < BIG_MOD - 2; i++) {
tmp[i] = acc;
acc = (acc * 2) % BIG_MOD;
}
INVERSES[0] = 0;
INVERSES[1] = 1;
for (i = 0; i < BIG_MOD - 2; i++) {
INVERSES[tmp[i]] = tmp[BIG_MOD - 3 - i];
}
}
long pow_mod(long a, long b, long mod, long acc) {
long powa = a % mod;
while (b > 0) {
if (b & 1) {
acc = (acc * powa) % mod;
}
powa = (powa * powa) % mod;
b >>= 1;
}
return acc;
}
long factorial_mod(long n, long mod, long acc) {
int i;
for (i = 2; i <= n; i++) {
acc = (acc * i) % mod;
}
return acc;
}
/* The actual logic */
struct adp {
long a;
long d;
long p;
long psum; // Cumulative sum of p values
long dpowp; // d ^ p
long dprod; // Cumulative product of d values
long dpowprod; // Cumulative product of d ^ p values
};
/* Read space-separated integers */
size_t read_ints(char *line, int **ints) {
if (line == NULL) {
return 0;
}
size_t size = INTS_START_SIZE;
*ints = malloc(INTS_START_SIZE * sizeof *ints);
if (*ints == NULL) {
return 0;
}
char *tok = line;
char *numend;
size_t i = 0;
long tmp;
while (*tok != '\n' && *tok != '\0') {
if (isspace(*tok)) {
tok++;
} else if (isdigit(*tok)) {
tmp = strtol(tok, &numend, 10);
if (i == size) {
// If we have filled array, double its size
size *= 2;
*ints = realloc(*ints, size * sizeof *ints);
if (*ints == NULL) {
return 0;
}
}
// store in array
(*ints)[i] = tmp;
i++;
tok = numend;
} else {
free(*ints);
*ints = NULL;
return 0;
}
}
return i;
}
int read_adp(char *buf, int n, struct adp *adp) {
int *ints;
size_t ints_len;
int i;
char *line;
long dpowp;
long psum = 0;
long dprod = 1;
long dpowprod = 1;
for (i = 0; i < n; i++) {
line = strtok(NULL, "\n");
ints_len = read_ints(line, &ints);
if (ints_len != 3) {
return 1;
}
adp[i].a = ints[0];
adp[i].d = ints[1];
adp[i].p = ints[2];
psum += adp[i].p;
adp[i].psum = psum;
dpowp = pow_mod(adp[i].d, adp[i].p, BIG_MOD, 1);
adp[i].dpowp = dpowp;
dprod = (dprod * adp[i].d) % BIG_MOD;
adp[i].dprod = dprod;
dpowprod = (dpowprod * dpowp) % BIG_MOD;
adp[i].dpowprod = dpowprod;
free(ints);
}
return 0;
}
// Calculate sum of p and product of d^p for [i, j[
void segtree_mcd(
struct adp *adp,
struct segtree *ptree,
int i,
int j,
long *k,
long *dprod)
{
if (!ptree) {
return;
}
// We need to calculate the sum of the p values
// and the product of the d^p at the same time
*k += ptree->v * (j-i);
// dtmp is the product of all d values in [i, j[
if (ptree->v > 0) {
long dtmp = adp[j-1].dprod;
if (i > 0) {
dtmp = (dtmp * INVERSES[adp[i-1].dprod]) % BIG_MOD;
}
*dprod = pow_mod(dtmp, ptree->v, BIG_MOD, *dprod);
}
int mid = (ptree->i + ptree->j) / 2;
if (j <= mid) {
segtree_mcd(adp, ptree->left, i, j, k, dprod);
return;
}
if (i >= mid) {
segtree_mcd(adp, ptree->right, i, j, k, dprod);
return;
}
// i < mid && j > mid
segtree_mcd(adp, ptree->left, i, mid, k, dprod);
segtree_mcd(adp, ptree->right, mid, j, k, dprod);
}
// Calculate and print for [i-1, j-1]
int min_const_diff(
int n,
struct adp *adp,
struct segtree *ptree,
int i,
int j)
{
if (i < 1 || j > n) {
return 1;
}
// k is initialized to the sum of initial p values in [i-1, j-1]
long k = adp[j-1].psum;
// dprod is initializaed to the product of d^p values in [i-1, j-1]
long dprod = adp[j-1].dpowprod;
if (i >= 2) {
k -= adp[i-2].psum;
dprod = (dprod * INVERSES[adp[i-2].dpowprod]) % BIG_MOD;
}
segtree_mcd(adp, ptree, i-1, j, &k, &dprod);
long v = factorial_mod(k, BIG_MOD, dprod);
printf("%ld %ld\n", k, v);
return 0;
}
// Flatten tree and add it to the adp array
void segtree_flatten(struct segtree *ptree, struct adp *adp, int n) {
if (!adp || !ptree) {
return;
}
segtree_flatten(ptree->left, adp, n);
segtree_free(ptree->left);
ptree->left = NULL;
segtree_flatten(ptree->right, adp, n);
segtree_free(ptree->right);
ptree->right = NULL;
if (ptree->v != 0) {
for (int k = ptree->i; k < ptree->j && k < n; k++) {
adp[k].p += ptree->v;
}
}
ptree->v = 0;
}
void update_adp(struct adp *adp, int n) {
int psum = 0;
int dpowprod = 1;
for (int i = 0; i < n; i++) {
psum += adp[i].p;
adp[i].psum = psum;
adp[i].dpowp = pow_mod(adp[i].d, adp[i].p, BIG_MOD, 1);
dpowprod = (dpowprod * adp[i].dpowp) % BIG_MOD;
adp[i].dpowprod = dpowprod;
}
}
int ptree_size = 0;
int add_powers(int n, struct adp *adp, struct segtree *ptree, int i, int j, int v) {
if (i < 1 || j > n) {
return 1;
}
//segtree_print(ptree);
//printf("Adding %ld to [%d,%d]\n", v, i, j);
segtree_add(ptree, i-1, j, v);
ptree_size++;
if (ptree_size * ptree_size >= n) {
//puts("Flattening the tree");
segtree_flatten(ptree, adp, n);
update_adp(adp, n);
ptree_size = 0;
}
//segtree_print(ptree);
return 0;
}
int handle_query(char *str, int n, struct adp *adp, struct segtree *ptree) {
int *ints;
int ints_len = read_ints(str, &ints);
if (ints_len < 1) {
return 1;
}
int query_type = ints[0];
if (query_type == 0) {
if (ints_len != 3) {
return 1;
}
return min_const_diff(n, adp, ptree, ints[1], ints[2]);
}
if (query_type == 1) {
if (ints_len != 4) {
return 1;
}
return add_powers(n, adp, ptree, ints[1], ints[2], ints[3]);
}
return 1;
}
int main(int argc, char **argv) {
// Prep work
calc_inverses();
char *buf = malloc(BUF_SIZE * sizeof *buf);
if (buf == NULL) {
return 0;
}
fread(buf, BUF_SIZE, 1, stdin);
char *line = strtok(buf, "\n");
char *end;
int n = strtol(line, &end, 10);
if ((!isspace(*end) && *end != '\0') || n < 1) {
return 0;
}
struct adp *adp = malloc(n * sizeof *adp);
struct segtree *ptree = segtree_new_simple(n);
if (adp == NULL || ptree == NULL) {
return 0;
}
int err = read_adp(buf, n, adp);
if (err) {
return 0;
}
line = strtok(NULL, "\n");
int q = strtol(line, &end, 10);
if ((!isspace(*end) && *end != '\0') || q < 1) {
return 0;
}
int i;
for (i = 0; i < q; i++) {
line = strtok(NULL, "\n");
err = handle_query(line, n, adp, ptree);
if (err) {
return 0;
}
}
return 0;
}