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Convert pseudocode to C

Codoritmo translates your algorithm into a C program ready to compile: it works out whether each variable is an int, a double, a bool or text, turns Escribir into printf and Leer into scanf, and declares your functions before main. It can also generate C++, with cout and cin.

Open this example and see its C

Opens the program in Codoritmo; choose C in View › Translate To.

The same algorithm in pseudocode and in C

The “GCD and LCM” example, with a function that uses Mientras and MOD, and the C that Codoritmo generates for it, untouched.

Pseudocode

MCDyMCM.psc · 25 lines
Funcion resultado <- MCD(a, b)    Definir resultado, resto Como Entero    // Algoritmo de Euclides    Mientras b <> 0 Hacer        resto <- a MOD b        a <- b        b <- resto    FinMientras    resultado <- aFinFuncionAlgoritmo MCDyMCM    Definir a, b, divisor Como Entero    Escribir "Primer número:"    Leer a    Escribir "Segundo número:"    Leer b    Si a <= 0 O b <= 0 Entonces        Escribir "Usa números enteros positivos."    SiNo        divisor <- MCD(a, b)        Escribir "MCD(", a, ", ", b, ") = ", divisor        Escribir "MCM(", a, ", ", b, ") = ", Trunc(a * b / divisor)    FinSiFinAlgoritmo

C generated by Codoritmo

MCDyMCM.c · 49 lines
/* Este código fue generado por Codoritmo a partir del pseudocódigo.   Puede que no sea completamente correcto: revíselo antes de usarlo. */#include<stdio.h>/* Funciones auxiliares, definidas al final */int truncar(double x);/* Declaraciones adelantadas de los subprocesos */int mcd(int a, int b);int main() {    int a = 0;    int b = 0;    int divisor = 0;    printf("Primer número:\n");    scanf("%d", &a);    printf("Segundo número:\n");    scanf("%d", &b);    if (a<=0 || b<=0) {        printf("Usa números enteros positivos.\n");    } else {        divisor = mcd(a, b);        printf("MCD(%i, %i) = %i\n", a, b, divisor);        printf("MCM(%i, %i) = %i\n", a, b, truncar((double)(a*b)/divisor));    }    return 0;}int mcd(int a, int b) {    int resto = 0;    int resultado = 0;    while (b!=0) {        resto = a%b;        a = b;        b = resto;    }    resultado = a;    return resultado;}/* Como trunc() de PSeInt: un valor a menos de 1e-11 del entero siguiente *//* se trunca a ese entero, así trunc(100*0.57) da 57 y no 56. */int truncar(double x) {    int t = (int)x;    if (t+1-x<1e-11) return t+1;    if (t-1-x>-1e-11) return t-1;    return t;}

This is exactly the code Codoritmo generates for this program, including the comment at the top, which is always in Spanish.

How to translate your pseudocode to C

  1. Write or open your algorithm

    It must be free of syntax errors; the Problems panel lists any.

  2. Choose C or C++

    In View › Translate To, choose C or C++. The code tab in the side panel shows the translation.

  3. Compare and copy

    The translation updates as you type. Copy it, or download it as .c or .cpp with File › Export As.

  4. Compile it

    With gcc: gcc program.c -o program -lm, then ./program. The -lm is needed when the code uses math.h.

Open this example and see its C

Opens the program in Codoritmo; choose C in View › Translate To.

What changes in C

C has no arrays sized with a value known only at run time, like Dimension datos[n]. In that case the code uses a fixed maximum size, ARREGLO_MAX (100), and explains it in a comment.

Text values are char arrays of 256 characters (MAX_STRLEN), including the terminating character.

C arrays start at 0: datos[i] becomes datos[i-1] when your profile uses 1-based arrays.

Aleatorio uses rand(). For different numbers on every run, add srand(time(NULL)); at the start of main and include time.h.

How each instruction is translated

Each row is one PSeInt instruction translated by Codoritmo inside a program with integers n and i, a real x, a text nombre and an array datos[5]. The output is generated when this page is built.

InstructionPSeIntC
Write (Escribir)
Escribir "Hola, ", nombre
printf("Hola, %s\n", nombre);
Write without a newline
Escribir Sin Saltar "Total: "
printf("Total: ");
Read an integer (Leer)
Leer n
scanf("%d", &n);
Read a real number
Leer x
scanf("%lf", &x);
Random number
n <- Aleatorio(1, 6)
n = (1+rand()%(6-1+1));
If … else (Si … SiNo)
Si n MOD 2 = 0 Entonces
    Escribir "par"
SiNo
    Escribir "impar"
FinSi
if (n%2==0) {
    printf("par\n");
} else {
    printf("impar\n");
}
Switch (Segun)
Segun n Hacer
    1: Escribir "uno"
    De Otro Modo: Escribir "otro"
FinSegun
switch (n) {
case 1:
    printf("uno\n");
    break;
default:
    printf("otro\n");
}
While (Mientras)
Mientras n > 0 Hacer
    n <- n - 1
FinMientras
while (n>0) {
    n = n-1;
}
Repeat … until (Repetir)
Repetir
    Leer n
Hasta Que n > 0
do {
    scanf("%d", &n);
} while (n<=0);
For (Para)
Para i <- 1 Hasta 10 Hacer
    Escribir i
FinPara
for (i=1; i<=10; ++i) {
    printf("%i\n", i);
}
Array element
datos[1] <- n
datos[0] = n;

Codoritmo and PSeInt desktop

PSeInt desktop also exports to C. These are the differences.

What Codoritmo adds

  • You see the translation next to the pseudocode, and it updates as you type.
  • It also exports to C#, PHP, Pascal, Visual Basic, QBasic, MatLab and HTML, like PSeInt.
  • It generates C and C++.

What PSeInt desktop does that Codoritmo doesn't yet

  • Its exporter has many years of classroom use; Codoritmo's is newer, so review the code before you hand it in.

Codoritmo is an independent project, inspired by PSeInt and compatible with its syntax and school profiles. It is not PSeInt and is not affiliated with it. Official PSeInt website

Frequently asked questions

Which compiler should I use?

Any standard C compiler: gcc, clang, or the one that comes with Dev-C++ or Code::Blocks.

C or C++?

Use the one your course asks for. The C version uses printf and scanf; the C++ one uses cout, cin and string.

Are subprocesses and functions translated?

Yes. Each SubProceso or Funcion becomes a C function, declared before main so it can be used in any order.

Why is there an ARREGLO_MAX?

Because your algorithm sizes an array with a variable. C needs the size at compile time, so room for 100 elements is reserved. If you need more, change the number in the #define.

Examples to try

Solved programs, each with its code, its flowchart and a sample run.

  • GCD and LCM

    Computes the greatest common divisor and the least common multiple.

    Intermediate

  • Times Table

    Prints the multiplication table for the number you choose.

    Beginner

  • Prime Numbers

    Finds every prime number up to a limit.

    Intermediate

  • Fibonacci Sequence

    Prints the first terms of the Fibonacci sequence.

    Beginner

By concept:Functions examplesMath examples

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