Sum from 1 to N Calculator

            from math import *

def sum_one_to_n(n) -> float:
    return ((n * (n + 1.0)) / 2.0)

assert abs(sum_one_to_n(100) - 5050) < 1e-6 * max(1.0, abs(5050))
          

            #include <assert.h>
#include <math.h>

double sum_one_to_n(double n) {
    return ((n * (n + 1.0)) / 2.0);
}

int main(void) {
    const double expected = 5050;
    const double actual = sum_one_to_n(100);
    assert(fabs(actual - expected) < 1e-6 * fmax(1.0, fabs(expected)));
}
          

            #include <cassert>
#include <cmath>
#include <numbers>

double sum_one_to_n(double n) {
    return ((n * (n + 1.0)) / 2.0);
}

int main() {
    constexpr double expected = 5050;
    const double actual = sum_one_to_n(100);
    assert(std::fabs(actual - expected) < 1e-6 * std::fmax(1.0, std::fabs(expected)));
}
          

x86-64 NASM · System V ABI · Linux · SSE2 with libm where required

            ; double sum_one_to_n(double n)
; Linux x86-64 NASM · System V ABI · first eight doubles in xmm0–xmm7
global sum_one_to_n
section .text

sum_one_to_n:
    push rbp
    mov rbp, rsp
    sub rsp, 48
    movsd [rbp-8], xmm0
    mov rax, 0x3ff0000000000000
    movq xmm0, rax
    movsd [rbp-40], xmm0
    movsd xmm0, [rbp-8]
    addsd xmm0, [rbp-40]
    movsd [rbp-32], xmm0
    movsd xmm0, [rbp-8]
    mulsd xmm0, [rbp-32]
    movsd [rbp-24], xmm0
    mov rax, 0x4000000000000000
    movq xmm0, rax
    movsd [rbp-48], xmm0
    movsd xmm0, [rbp-24]
    divsd xmm0, [rbp-48]
    movsd [rbp-16], xmm0
    movsd xmm0, [rbp-16]
    leave
    ret
          

            function result = sum_one_to_n(n)
    result = ((n * (n + 1.0)) / 2.0);
end
          

            ClearAll[mwCalculate];
mwCalculate[n_] := ((n * (n + 1.0)) / 2.0);