CODE:

#include 
#include 
#include "kota_string.h"

void divide_formula( char *formula, double *figure, char *symbol);
double calculate( double *figure, char *symbol);
void batsu();

int kou_num = 0;

int main( )
{
	setbuf(stdout,0);//msPEwb2Kの制限：main関数の最初の実行文の前に置く

	char formula[100] = {"\0"}, symbol[100] = {"\0"};
	double figure[100] = {0}, sum = 0;

	printf("式：");
	fgets( formula, sizeof(formula), stdin);

	if( strchr( formula, '\n') != NULL ) {
		// 改行文字を終端記号に置換
		formula[ kota_strlen(formula) - 1] = '\0';
	} else {
		// 入力ストリームをクリア
		while( getchar() != '\n' );
	}

	divide_formula( formula, figure, symbol );	//式を文字と記号に分ける
	sum = calculate( figure, symbol );	//計算する

	printf("Ans：%f\n", sum);

	batsu();
	return 0;
}

/********************* divide_formula( ) **********************/
//数字と記号を分ける
void divide_formula( char * formula, double *figure, char *symbol)
{
	char fig[20];
	int i=0, j=0,cnt = 0;
	for(kou_num = 0; *formula != '\0'; formula++){
		if( !(*formula >= '0' && *formula = '0' && *formula = '0' && *formula <= '9' || (*formula == '.') ){
			fig[j] = *formula;
			j ++;
			formula ++;
		}
		sscanf(fig, "%lf", figure);
		figure -= kou_num;
		symbol -= kou_num;
}

double calculate(double *figure, char *symbol)
{
	double sum = 0;
	int i;
	sum = *figure;

	for(i = 0; i < kou_num; i++){
		figure ++;
		switch( *symbol )
		{
			case '+':
				sum += (double)*figure;
				break;
			case '-':
				sum -= (double)*figure;
				break;
			case '*':
				sum *= (double)*figure;
				break;
			case '/':
				sum /= (double)*figure;
				break;
			default :
				puts("入力エラー");
				exit(1);
		}
		symbol ++;
	}
	return sum;
}
void batsu()
{
	int size = 0, i, j;
	printf("\n(おまけ)×の大きさ:"); scanf("%d",&size);
	for(i = 0; i < size; i++){
		for(j = 0; j < size; j ++)
			printf("%s", (i == j || (i + j) == (size - 1 ))?"　":"＊");
		putchar('\n');
	}
}