Function_Pointer

.gitignore

@@ -0,0 +1,2 @@
+*.o
+/calc

calc.c

@@ -5,29 +5,33 @@ int main(){
 	FILE *fp = NULL;
 	int operand1, operand2;
 	char operator = ' ';
-	int result, line = 0;
-
+	int result, line,i = 0;
+	double (*func)(int,int);
 	fp = fopen("read.txt","r");
 	if(fp!=NULL){
 		fscanf(fp, "%d", &line);
 
-		for(int i=0; i<line; i++) {
+		for(i=0; i<line; i++) {
 			fscanf(fp, "%d %c %d",&operand1, &operator, &operand2);
-			switch(operator) {
+			if(feof(fp) == 1)
+				break;
+				switch(operator) {
 				case '+':
-				result = add(operand1, operator);
+				func = add;
 				break;
 				case '-':
-				result = minus(operand1, operator);
+				func = minus;
 				break;
 				case '*':
-				result = mul(operand1, operator);
+				func = mul;
+				break;
 				case '/':
-				result = div(operand1, operator);
+				func = div;
 				break;
-			}		
-			printf("%d %c %d = %d\n",
-				 operand1, operator, operand2, result);
+			}
+			result = func(operand1, operand2);		
+			printf("%d %c %d = %lf\n",
+				 operand1, operator, operand2, (double)result);
 		}
 	}
 	return 0;

operators.c

@@ -1,16 +1,16 @@
 #include "operators.h"
 
-int add(int op1, int op2) {
+double add(int op1, int op2) {
 	return op1+op2;
 }
-int minus(int op1, int op2) {
+double minus(int op1, int op2) {
 	return op1-op2;
 }
-int mul(int op1, int op2) {
+double mul(int op1, int op2) {
 	return op1*op2;
 }
 
-int div(int op1, int op2) {
-	return op1%op2;
+double div(int op1, int op2) {
+	return (double) op1/op2;
 }
 

operators.h

@@ -1,4 +1,4 @@
-int add(int op1, int op2);
-int mul(int op1, int op2);
-int div(int op1, int op2);
-int minus(int op1, int op2);
+double add(int op1, int op2);
+double mul(int op1, int op2);
+double div(int op1, int op2);
+double minus(int op1, int op2);