Calculadora - linguagem c

Se tem um programa que tanto impressiona um iniciante em programação
principalmente Linguagem C, é Calculadora,
O triunfo dos que estavam aprendendo eletrônica básica a alguns anos atrás quando eu também cursava isto, era montar um rádio.
Oh! que alegria era ver um radinho funcionando, depois de tantos esforços para montá-lo olhando o esquema técnico e soldando componente a componente, com muito cuidado para não inverter as polaridades dos semicondutores, tempos de ouro que não voltam mais, que saudades!
 Bom, o programa é todo baseado em funções simples, e na função do Menu: Menucalculadora(); coloquei um switch case que é perfeito para escolha e muito simples de usar, se for digitado algo que não esteja nas opções o comando default entra em ação e aciona um bip, advertindo o usuário sobre seu erro, e o comando do while, onde a variável de controle é diferente de 0 faz a repetição remontando tudo do jeito que estava no início.
Programa especialmente indicado a iniciantes em Linguagem C.

Eis as saídas deste programa no cmd:

Eis o Código abaixo:

#include <stdio.h>

#include <conio.h>

#include <math.h>

void Janela5 ( ) {

     int lin, col;

     col = 0;

     for ( lin = 0; lin <= 25 ; lin++ ) {

         for ( col = 0; col <= 80 ; col++ ) {

              gotoxy ( col , lin );

              if ( lin == 2 ) {

                   textbackground ( LIGHTBLUE );

                   printf ( " " );

              }

              if ( col == 1 ) {

                   textbackground ( LIGHTBLUE );

                   printf ( " " );

              }

              if ( lin == 25 ) {

                   textbackground ( LIGHTBLUE );

              }

              if ( col == 80 ) {

                   textbackground ( LIGHTBLUE );

                   printf ( " " );

              }

         }

     }

     textbackground ( BLACK );

}

void Menucalculadora ( );

float n1, n2, porcentagem, resultado;

int load, col, timer;

void Funcsoma ( ) {

     system ( "cls" );

     Janela5 ( );

     textcolor ( LIGHTRED );

     gotoxy ( 32 , 3 );

     printf ( "PROGRAMA CALCULOS" );

     textcolor ( LIGHTBLUE );

     gotoxy ( 35 , 5 );

     printf ( "CALCULADORA" );

     textcolor ( YELLOW );

     gotoxy ( 38 , 7 );

     printf ( "ADICAO " );

     textcolor ( LIGHTGRAY );

     gotoxy ( 31 , 9 );

     printf ( "Digite um numero: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &n1 );

     fflush ( stdin );

     textcolor ( LIGHTGRAY );

     gotoxy ( 31 , 11 );

     printf ( "Digite outro numero: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &n2 );

     fflush ( stdin );

     resultado = n1 + n2;

     textcolor ( LIGHTGREEN );

     gotoxy ( 31 , 13 );

     printf ( "O resultado e: " );

     textcolor ( LIGHTRED );

     gotoxy ( 47 , 13 );

     printf ( "%.2f\n" , resultado );

     getche ( );

     system ( "cls" );

}

void Funcsubtrai ( ) {

     system ( "cls" );

     Janela5 ( );

     textcolor ( LIGHTRED );

     gotoxy ( 32 , 3 );

     printf ( "PROGRAMA CALCULOS" );

     textcolor ( LIGHTBLUE );

     gotoxy ( 35 , 5 );

     printf ( "CALCULADORA" );

     textcolor ( YELLOW );

     gotoxy ( 36 , 7 );

     printf ( "SUBTRACAO " );

     textcolor ( LIGHTGRAY );

     gotoxy ( 31 , 9 );

     printf ( "Digite um numero: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &n1 );

     fflush ( stdin );

     textcolor ( LIGHTGRAY );

     gotoxy ( 31 , 11 );

     printf ( "Digite outro numero: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &n2 );

     fflush ( stdin );

     resultado = n1 - n2;

     textcolor ( LIGHTGREEN );

     gotoxy ( 31 , 13 );

     printf ( "O resultado e: " );

     textcolor ( LIGHTRED );

     gotoxy ( 47 , 13 );

     printf ( "%.2f\n" , resultado );

     getche ( );

     system ( "cls" );

}

void Funcmult ( ) {

     system ( "cls" );

     Janela5 ( );

     textcolor ( LIGHTRED );

     gotoxy ( 32 , 3 );

     printf ( "PROGRAMA CALCULOS" );

     textcolor ( LIGHTBLUE );

     gotoxy ( 35 , 5 );

     printf ( "CALCULADORA" );

     textcolor ( YELLOW );

     gotoxy ( 36 , 7 );

     printf ( "MULTIPLICACAO " );

     textcolor ( LIGHTGRAY );

     gotoxy ( 31 , 9 );

     printf ( "Digite um numero: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &n1 );

     fflush ( stdin );

     textcolor ( LIGHTGRAY );

     gotoxy ( 31 , 11 );

     printf ( "Digite outro numero: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &n2 );

     fflush ( stdin );

     resultado = n1 * n2;

     textcolor ( LIGHTGREEN );

     gotoxy ( 31 , 13 );

     printf ( "O resultado e: " );

     textcolor ( LIGHTRED );

     gotoxy ( 47 , 13 );

     printf ( "%.2f\n" , resultado );

     getche ( );

     system ( "cls" );

}

void Funcdiv ( ) {

     system ( "cls" );

     Janela5 ( );

     textcolor ( LIGHTRED );

     gotoxy ( 32 , 3 );

     printf ( "PROGRAMA CALCULOS" );

     textcolor ( LIGHTBLUE );

     gotoxy ( 35 , 5 );

     printf ( "CALCULADORA" );

     textcolor ( YELLOW );

     gotoxy ( 37 , 7 );

     printf ( "DIVISAO " );

     textcolor ( LIGHTGRAY );

     gotoxy ( 31 , 9 );

     printf ( "Digite um numero: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &n1 );

     fflush ( stdin );

     textcolor ( LIGHTGRAY );

     gotoxy ( 31 , 11 );

     printf ( "Digite outro numero: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &n2 );

     fflush ( stdin );

     resultado = n1 / n2;

     textcolor ( LIGHTGREEN );

     gotoxy ( 31 , 13 );

     printf ( "O resultado e: " );

     textcolor ( LIGHTRED );

     gotoxy ( 47 , 13 );

     printf ( "%.2f\n" , resultado );

     getche ( );

     system ( "cls" );

}

void Funcadporcent ( ) {

     system ( "cls" );

     Janela5 ( );

     textcolor ( LIGHTRED );

     gotoxy ( 32 , 3 );

     printf ( "PROGRAMA CALCULOS" );

     textcolor ( LIGHTBLUE );

     gotoxy ( 35 , 5 );

     printf ( "CALCULADORA" );

     textcolor ( YELLOW );

     gotoxy ( 29 , 7 );

     printf ( "ADICAO COM PORCENTAGENS" );

     textcolor ( LIGHTGRAY );

     gotoxy ( 31 , 9 );

     printf ( "Digite um numero: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &n1 );

     fflush ( stdin );

     textcolor ( LIGHTGRAY );

     gotoxy ( 19 , 11 );

     printf ( "Digite o valor da porcentagem Sem o simbolo %%: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &porcentagem );

     fflush ( stdin );

     resultado = ( n1 + ( n1 * ( porcentagem / 100 ) ) );

     textcolor ( LIGHTGREEN );

     gotoxy ( 31 , 13 );

     printf ( "O resultado e: " );

     textcolor ( LIGHTRED );

     gotoxy ( 47 , 13 );

     printf ( "%.2f\n" , resultado );

     getche ( );

     system ( "cls" );

}

void Funcsubporcent ( ) {

     system ( "cls" );

     Janela5 ( );

     textcolor ( LIGHTRED );

     gotoxy ( 32 , 3 );

     printf ( "PROGRAMA CALCULOS" );

     textcolor ( LIGHTBLUE );

     gotoxy ( 35 , 5 );

     printf ( "CALCULADORA" );

     textcolor ( YELLOW );

     gotoxy ( 29 , 7 );

     printf ( "SUBTRACAO COM PORCENTAGENS" );

     textcolor ( LIGHTGRAY );

     gotoxy ( 31 , 9 );

     printf ( "Digite um numero: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &n1 );

     fflush ( stdin );

     textcolor ( LIGHTGRAY );

     gotoxy ( 19 , 11 );

     printf ( "Digite o valor da porcentagem Sem o simbolo %%: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &porcentagem );

     fflush ( stdin );

     resultado = ( n1 - ( n1 * ( porcentagem / 100 ) ) );

     textcolor ( LIGHTGREEN );

     gotoxy ( 31 , 13 );

     printf ( "O resultado e: " );

     textcolor ( LIGHTRED );

     gotoxy ( 47 , 13 );

     printf ( "%.2f\n" , resultado );

     getche ( );

     system ( "cls" );

}

void Funcmultporcent ( ) {

     system ( "cls" );

     Janela5 ( );

     textcolor ( LIGHTRED );

     gotoxy ( 32 , 3 );

     printf ( "PROGRAMA CALCULOS" );

     textcolor ( LIGHTBLUE );

     gotoxy ( 35 , 5 );

     printf ( "CALCULADORA" );

     textcolor ( YELLOW );

     gotoxy ( 29 , 7 );

     printf ( "MULTIPLICACAO COM PORCENTAGENS" );

     textcolor ( LIGHTGRAY );

     gotoxy ( 31 , 9 );

     printf ( "Digite um numero: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &n1 );

     fflush ( stdin );

     textcolor ( LIGHTGRAY );

     gotoxy ( 19 , 11 );

     printf ( "Digite o valor da porcentagem Sem o simbolo %%: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &porcentagem );

     fflush ( stdin );

     resultado = ( n1 * ( porcentagem / 100 ) );

     textcolor ( LIGHTGREEN );

     gotoxy ( 31 , 13 );

     printf ( "O resultado e: " );

     textcolor ( LIGHTRED );

     gotoxy ( 47 , 13 );

     printf ( "%.2f\n" , resultado );

     getche ( );

     system ( "cls" );

}

void Funcdiviporcent ( ) {

     system ( "cls" );

     Janela5 ( );

     textcolor ( LIGHTRED );

     gotoxy ( 32 , 3 );

     printf ( "PROGRAMA CALCULOS" );

     textcolor ( LIGHTBLUE );

     gotoxy ( 35 , 5 );

     printf ( "CALCULADORA" );

     textcolor ( YELLOW );

     gotoxy ( 29 , 7 );

     printf ( "DIVISAO COM PORCENTAGENS" );

     textcolor ( LIGHTGRAY );

     gotoxy ( 31 , 9 );

     printf ( "Digite um numero: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &n1 );

     fflush ( stdin );

     textcolor ( LIGHTGRAY );

     gotoxy ( 19 , 11 );

     printf ( "Digite o valor da porcentagem Sem o simbolo %%: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &porcentagem );

     fflush ( stdin );

     if ( n1 != 0 && porcentagem != 0 )

         resultado = ( n1 / ( porcentagem / 100 ) );

     textcolor ( LIGHTGREEN );

     gotoxy ( 31 , 13 );

     printf ( "O resultado e: " );

     textcolor ( LIGHTRED );

     gotoxy ( 47 , 13 );

     printf ( "%.2f\n" , resultado );

     getche ( );

     system ( "cls" );

}

void Funcraiz ( ) {

     system ( "cls" );

     Janela5 ( );

     textcolor ( LIGHTRED );

     gotoxy ( 32 , 3 );

     printf ( "PROGRAMA CALCULOS" );

     textcolor ( LIGHTBLUE );

     gotoxy ( 35 , 5 );

     printf ( "CALCULADORA" );

     textcolor ( YELLOW );

     gotoxy ( 35 , 7 );

     printf ( "RAIZ QUADRADA " );

     textcolor ( LIGHTGRAY );

     gotoxy ( 31 , 9 );

     printf ( "Digite um numero: " );

     textcolor ( LIGHTRED );

     scanf ( "%f" , &n1 );

     fflush ( stdin );

     textcolor ( LIGHTGREEN );

     gotoxy ( 31 , 11 );

     printf ( "A raiz quadrada e: " );

     textcolor ( LIGHTRED );

     gotoxy ( 50 , 11 );

     printf ( "%.2f\n" , sqrt ( n1 ) );

     getche ( );

     system ( "cls" );

}

void LOADING ( ) {

     textcolor ( LIGHTGREEN );

     gotoxy ( 32 , 15 );

     printf ( "LOADING " );

     col = 31;

     load = 200;

     for ( timer = 0; timer <= 13 ; timer++ ) {

         col++;

         //gotoxy(41,15);

         Sleep ( load );

         textcolor ( LIGHTRED );

         printf ( "%c" , 16 );

         if ( col == 35 )

              load = load - 100;

     }

}

void BEMVINDO ( ) {

     void Inicio ( );

     system ( "cls" );

     Janela5 ( );

     char name [ 20 ] [ 20 ];

     int aux;

     for ( aux = 0; aux < 50 ; aux++ ) {

         textcolor ( LIGHTRED );

         gotoxy ( 35 , 3 );

         printf ( "PROGRAMA CALCULOS" );

         textcolor ( LIGHTBLUE );

         gotoxy ( 26 , 5 );

         printf ( "SEJA BEM VINDO AO PROGRAMA CALCULOS" );

         textcolor ( YELLOW );

         gotoxy ( 27 , 7 );

         printf ( "POR FAVOR, DIGITE SEU NOME ABAIXO" );

         textcolor ( LIGHTGRAY );

         gotoxy ( 35 , 9 );

         printf ( "NOME: " );

         textcolor ( LIGHTRED );

         gotoxy ( 42 , 9 );

         gets ( name [ aux ] );

         fflush ( stdin );

         textcolor ( LIGHTBLUE );

         gotoxy ( 31 , 11 );

         printf ( " SEJA BEM VINDO" );

         textcolor ( LIGHTRED );

         gotoxy ( 49 , 11 );

         printf ( "%s" , name [ aux ] );

         textcolor ( YELLOW );

         gotoxy ( 31 , 13 );

         printf ( "PRESSIONE QUALQUER TECLA" );

         getche ( );

         LOADING ( );

         Sleep ( 800 );

         Inicio ( );

     }

}

void Inicio ( ) {

     char ch;

     system ( "cls" );

     do {

         Janela5 ( );

         textcolor ( LIGHTRED );

         gotoxy ( 35 , 8 );

         printf ( "PROGRAMA CALCULOS" );

         textcolor ( YELLOW );

         gotoxy ( 24 , 10 );

         printf ( "Programa desenvolvido por:" );

         textcolor ( LIGHTCYAN );

         gotoxy ( 51 , 10 );

         printf ( "Samuel Lima" );

         textcolor ( LIGHTGREEN );

         gotoxy ( 34 , 12 );

         printf ( "sa_sp10@hotmail.com" );

         textcolor ( LIGHTBLUE );

         gotoxy ( 24 , 14 );

         printf ( "DIGITE    PARA SAIR OU   PARA CONTINUAR  " );

         textcolor ( LIGHTRED );

         gotoxy ( 32 , 14 );

         printf ( "S" );

         textcolor ( LIGHTRED );

         gotoxy ( 47 , 14 );

         printf ( "C" );

         gotoxy ( 40 , 18 );

         ch = getche ( );

         fflush ( stdin );

         switch ( ch ) {

              case 'S':

                   textcolor ( LIGHTRED );

                   gotoxy ( 35 , 18 );

                   printf ( "\aO ROCCO AGRADECE" );

                   Sleep ( 1800 );

                   exit ( 0 );

                   break;

              case 'C':

                   Menucalculadora ( );

                   break;

              default:

                   textcolor ( LIGHTRED );

                   gotoxy ( 35 , 16 );

                   printf ( "\aOPCAO ERRADA" );

                   Sleep ( 1800 );

                   system ( "cls" );

                   break;

         }

     } while ( 1 );

}

void Menucalculadora ( ) {

     int op;

     system ( "cls" );

     do {

         Janela5 ( );

         textcolor ( LIGHTRED );

         gotoxy ( 32 , 3 );

         printf ( "PROGRAMA CALCULOS" );

         textcolor ( LIGHTBLUE );

         gotoxy ( 35 , 5 );

         printf ( "CALCULADORA" );

         textcolor ( YELLOW );

         gotoxy ( 29 , 7 );

         printf ( "ESCOLHA UMA OPCAO ABAIXO" );

         textcolor ( LIGHTCYAN );

         gotoxy ( 29 , 9 );

         printf ( " 1 - ADICAO" );

         gotoxy ( 29 , 10 );

         printf ( " 2 - SUBTRACAO" );

         gotoxy ( 29 , 11 );

         printf ( " 3 - MULTIPLICACAO" );

         gotoxy ( 29 , 12 );

         printf ( " 4 - DIVISAO" );

         gotoxy ( 29 , 13 );

         printf ( " 5 - ADICAO COM PORCENTAGENS" );

         gotoxy ( 29 , 14 );

         printf ( " 6 - SUBTRACAO COM PORCENTAGENS" );

         gotoxy ( 29 , 15 );

         printf ( " 7 - MULTIPLICACAO COM PORCENTAGENS" );

         gotoxy ( 29 , 16 );

         printf ( " 8 - DIVISAO COM PORCENTAGENS" );

         gotoxy ( 29 , 17 );

         printf ( " 9 - RAIZ QUADRADA" );

         gotoxy ( 29 , 18 );

         printf ( "10 - SAIR DO PROGRAMA" );

         gotoxy ( 29 , 19 );

         printf ( "11 - VOLTAR AO INICIO DO PROGRAMA" );

         gotoxy ( 37 , 21 );

         textcolor ( LIGHTRED );

         scanf ( "%d" , &op );

         fflush ( stdin );

         switch ( op ) {

              case 1:

                   Funcsoma ( );

                   break;

              case 2:

                   Funcsubtrai ( );

                   break;

              case 3:

                   Funcmult ( );

                   break;

              case 4:

                   Funcdiv ( );

                   break;

              case 5:

                   Funcadporcent ( );

                   break;

              case 6:

                   Funcsubporcent ( );

                   break;

              case 7:

                   Funcmultporcent ( );

                   break;

              case 8:

                   Funcdiviporcent ( );

                   break;

              case 9:

                   Funcraiz ( );

                   break;

              case 10:

                   textcolor ( LIGHTRED );

                   gotoxy ( 35 , 21 );

                   printf ( "\aO ROCCO AGRADECE" );

                   Sleep ( 1800 );

                   exit ( 0 );

                   break;

              case 11:

                   BEMVINDO ( );

                   break;

              default:

                   textcolor ( LIGHTRED );

                   gotoxy ( 35 , 21 );

                   printf ( "\aOPCAO INVALIDA" );

                   getche ( );

                   system ( "cls" );

                   break;

         }

     } while ( op != 0 );

}

int main ( ) {

     system ( "title PROGRAMA CALCULOS" );

     BEMVINDO ( );

}