how to use mathemathical symbol in switch(URGENT)

[Azka]

i have a problem to enter the input A+ or B+ in switch case
any body can help to solve my problem
program like this

#include <stdio.h>
int main()
{ //start program
    int part,sol,com,cir,mat,wav,lan,anw;
    float no1,no2,no3,no4,no5,no6,gpa,cgpa,res,total=17;
    char c1,c2,c3,c4,c5,c6,q;
      int loop=1;
    while (loop==1)
    {// start while
    printf("Enter part of sem: ");
    scanf("%d",&part);
 
    if (part==4)//start if
    {
        printf("Enter grade for the following subject\n");
 
        printf("Solid State: ");
        scanf("%c",&c1);
        sol=getchar();
        switch (sol) { //start switch1
            case 'A' :
            case 'a' :
            case 'A+':
            case 'a+':no1=4.00*3.00;
            break;
 
            case 'a-':
            case 'A-':no1=3.67*3.00;
            break;
 
            case 'B+':
            case 'b+':    no1=3.33*3.00;
            break;
 
            case 'B':
            case 'b':    no1=3.00*3.00;
            break;
 
            case 'B-':
            case 'b-':    no1=2.67*3.00;
            break;
 
            case 'C+':
            case 'c+': no1=2.33*3.00;
            break;
 
            case 'C':
            case 'c': no1=2.00*3.00;
            break;
 
            case 'C-':
            case 'c-': no1=1.67*3.00;
            break;
 
            case 'D+':
            case 'd+': no1=1.33*3.00;
            break;
 
            case 'D':
            case 'd': no1=1.00*3.00;
            break;
 
            default: printf("wrong input");
            break;
            }// end switch1
 
//output program
    printf("Solid State:\t%c\n%.2f",sol,no1);
 
return 0;
 
} // program terminated

[horace1]

the case values should be integer constants (ints, chars, etc). e.g.

        switch (sol) { //start switch1
            case '+':no1=4.00+3.00;
            break;
            case '*':no1=4.00*3.00;
            break;