카타 7급 Functions of Integers on Cartesian Plane

1 C

unsigned long long sumin(unsigned long long n) {
  return (n * (n + 1) * (2 * n + 1)) / 6;
}
unsigned long long sumax(unsigned long long n) {
  return ((n * (n + 1) * (4 * n - 1))) / 6;
}
unsigned long long sumsum(unsigned long long n) {
  return n * n * (n + 1);
}

2 R

sumin <- function(n) {
  (n * (n + 1) * (2 * n + 1)) %/% 6
}

sumax <- function(n) {
  ((n * (n + 1) * (4 * n - 1))) %/% 6
}

sumsum <- function(n) {
  n * n * (n + 1)
}

sumin <- function(n) {
  sum(sapply(1:n, function(x){sum(1:x) + x * (n-x)}))
}

sumax <- function(n) {
  sum(sapply(1:n, function(x){sum(x:n) + x * (x-1)}))
}

sumsum <- function(n) {
 sum(1:n) * n * 2
}

sumin <- function(n) {
  s = 0
  for(i in 1:n) {
    s = s+(2*(n-i)+1)*i
  }
  s
}

sumax <- function(n) {
  s = 0
  for(i in 1:n) {
    s = s+(2*i-1)*i
  }
  s
}

sumsum <- function(n) {
  s = 0
  for(i in 1:n) {
    for(j in 1:n) {
      s = s + i + j
    }
  }
  s
}