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const std = @import("std");
const print = std.debug.warn;
fn p1() void {
var i: usize = 0;
var sum: usize = 0;
while (i < 1000) : (i += 1) {
if (i % 3 == 0) {
sum += i;
} else if (i % 5 == 0) {
sum += i;
}
}
std.debug.warn("{}\n", .{sum});
}
fn p2() void {
const size: usize = 35;
var array: [size]usize = undefined;
for (array) |_, i| {
array[i] = 0;
}
array[0] = 1;
array[1] = 2;
var i: usize = 2;
while (i < size) : (i += 1) {
array[i] = array[i - 1] + array[i - 2];
}
i = 0;
var sum: usize = 0;
while (array[i] < 4_000_000) : (i += 1) {
if (array[i] % 2 == 0)
sum += array[i];
}
std.debug.warn("{}\n", .{sum});
}
fn is_prime(k: usize) bool {
var i: usize = 2;
var divided: bool = false;
while (i < k) : (i += 1) {
if (k % i == 0) {
divided = true;
break;
}
}
return !divided;
}
fn p3() void {
const size: usize = 5000;
var primes: [size]usize = undefined;
var i: usize = 1;
var j: usize = 0;
while (j < size) : (i += 1) {
if (is_prime(i)) {
primes[j] = i;
j += 1;
}
}
const n: usize = 600851475143;
//const n: usize = 13195;
var biggest: usize = 0;
for (primes) |prime| {
if (n % prime == 0) {
biggest = prime;
}
}
std.debug.warn("{}\n", .{biggest});
}
fn p4() !void {
var i: usize = 0;
var j: usize = 0;
var str: [6]u8 = undefined;
var largest: usize = 0;
while (i < 1000) : (i += 1) {
j = 0;
while (j < 1000) : (j += 1) {
_ = try std.fmt.bufPrint(&str, "{}", .{i * j});
if (i * j > largest and
str[0] == str[5] and
str[1] == str[4] and
str[2] == str[3])
{
largest = i * j;
}
}
}
print("{}\n", .{largest});
}
fn p5() void {
var num: usize = 20;
var i: usize = 1;
var j: usize = 0;
var found: bool = false;
while (i < 1_500_000_000) : (i += 1) {
j = num;
found = false;
while (j != 0) : (j -= 1) {
if (i % j != 0) {
found = true;
}
}
if (!found) {
print("{}\n", .{i});
break;
}
}
}
fn p6() void {
var sum_0: usize = 0;
var sum_1: usize = 0;
var i: usize = 1;
while (i <= 100) : (i += 1) {
sum_0 += i * i;
sum_1 += i;
}
sum_1 *= sum_1;
print("{}\n", .{sum_1 - sum_0});
}
fn p7() void {
const size: usize = 10_002;
var primes: [size]usize = undefined;
var i: usize = 1;
var j: usize = 0;
while (j < size) : (i += 1) {
if (is_prime(i)) {
primes[j] = i;
j += 1;
}
}
print("{}\n", .{primes[size - 1]});
}
fn p8() void {}
pub fn main() !void {
//p1();
//p2();
//p3();
//_ = try p4();
//p5();
//p6();
//p7();
p8();
}
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