@suzusen0201先生による電卓コードをご覧ください

gistfile1.c

#include <stdio.h>
#include<stdlib.h>
#include<string.h>
/*乗算=mul,割り算=div,足し算=add,引き算=sub,乗除算=mad*/
void mad(char *,int,char *);
void absu(char *,int,char *);
void main(void)
{
	char siki[100],p[100],siki2[100],sikia[1000],sikiA[1000],sikiB[1000];
	int i,A,B,a,b,X,c,d,e,judb,juda,judaaa,bbb,counta,countb,jud1,jud2,jud,i2,i3,aaa,x,y,xa,y1,yyy,xxx,ii;
	juda=0;
	judb=0;
	jud=0;
	i=0;
	printf("数式を半角で入力してください=>");
	scanf("%s",siki);
	while(siki[i]!='\0'){
		if((siki[i]>='0')&&(siki[i]<='9')||(siki[i]=='*')||(siki[i]=='/')||(siki[i]=='+')||(siki[i]=='-')||(siki[i]=='(')||(siki[i]==')')||(siki[i]=='{')||(siki[i]=='}')){
			i++;
		}
		else{
			printf("不正な文字入力があります\n");
			exit(1);
		}
	}

	/*括弧の判定*/
	i=0;
	while(siki[i]!='\0'){
		if(siki[i]=='('){
			juda++;
		}
		else if(siki[i]==')'){
			judb++;
		}
		i++;
	}
	/*printf("%d\n",jud1);*/
	/*printf("%d\n",jud2);*/

	if(juda==judb){
	
	}
	else{
	printf("エラーです。括弧を確認してください。\n");
	exit(1);
	}

	while(jud!=juda){
	A=0;
	B=0;
	i=0;
		while(siki[i]!='\0'){
			if(siki[i]=='('){
				A=i;
				a=i;/*「(」の位置*/
				A++;
			}
			if(siki[i]==')'){
				B=i;
				b=i;/*「)」の位置*/
				B--;
			}
			if((siki[a]=='(')&&(siki[b]==')')){
				for(X=0;A<=B;X++){
				p[X]=siki[A];
				A++;
			}
			p[X]='\0';
			break;
 
			}
			i++;
		}

	/*printf("%s\n",p);*/




	sikia[0]='\0';

	sikiA[0]='\0';

	sikiB[0]='\0';








	aaa=0;
	counta=0;
	countb=0;
	bbb=0;
	jud1=0;


		while(p[counta]!='\0'){
			if((p[counta]=='*')||(p[counta]=='/')){
				aaa++;
			}
			counta++;
		}
		while(p[countb]!='\0'){
			if((p[countb]=='+')||(p[countb]=='-')){
				bbb++;
			}
			countb++;
		}

	while(jud1!=aaa){
		i=0;
		while(p[i]!='\0'){
			if((p[i]=='*')||(p[i]=='/')){
				x=i;
				x--;
				y=i;
				y++;
				
				while(x!=0){
					if((p[x]>='0')&&(p[x]<='9')){
						x--;
					}
					else{
						break;
					}
				}
		


				if((p[x]=='*')||(p[x]=='/')||(p[x]=='+')){
					x++;					
				}
				else if(p[x]=='-'){
				}
				else{

				}

				/*printf("%d\n",x);*/		
				xa=x;



				while(p[y]!='\0'){
					if((p[y]>='0')&&(p[y]<='9')){
						y++;
					}
					else{
						break;
					}
				}
				/*if((siki[y]=='*')||(siki[y]=='/')||(siki[y]=='+')||(siki[y]=='-')){
					y--;					
				}

				else{
					

				}*/

				/*printf("%d\n",y);*/
				y1=y;

				i2=0;
				
				while(x!=y){
					sikia[i2]=p[x];
					i2++;
					x++;
				}
				sikia[i2]='\0';
				/*printf("%s☆\n",sikia);*/

				i3=0;
				while(sikia[i3]!='\0'){
					if((sikia[i3]=='*')||(sikia[i3]=='/')){
						mad(sikia,i3,sikia);
						break;
					}
					i3++;
				}


				/*printf("%s\n",sikia);*/
				strcpy(sikiA,p);

				c=0;
				while(sikia[c]!='\0'){
					sikiA[xa]=sikia[c];
					c++;
					xa++;
				}
				while(p[y1]!='\0'){
					sikiA[xa]=p[y1];
					y1++;
					xa++;
				}/*
				while(siki){
					sikiA[xa]=*/
				sikiA[xa]='\0';
				p[0]='\0';
				strcpy(p,sikiA);
				/*printf("%s\n",siki);*/
				/*printf("%d\n",aaa);*/
				/*printf("%s\n",p);*/
				break;
			}

			else{
				i++;
			}

		}
		jud1++;
	}
/*printf("%s\n",p);*/







	sikia[0]='\0';

	sikiA[0]='\0';

	sikiB[0]='\0';


	jud2=0;




	while(jud2!=bbb){
		i=0;

		while(p[i]!='\0'){
			if(p[0]=='-'){
				i++;
			}
			else if((p[i]=='+')||(p[i]=='-')){
				x=i;
				x--;
				y=i;
				y++;
				
				while(x!=0){
					if((p[x]>='0')&&(p[x]<='9')){
						x--;
					}
					else{
						break;
					}
				}
		


				if((p[x]=='*')||(p[x]=='/')||(p[x]=='+')){
					x++;					
				}
				else if(p[x]=='-'){
				}
				else{

				}

				/*printf("%d\n",x);*/		
				xa=x;



				while(p[y]!='\0'){
					if((p[y]>='0')&&(p[y]<='9')){
						y++;
					}
					else{
						break;
					}
				}
				/*if((siki[y]=='*')||(siki[y]=='/')||(siki[y]=='+')||(siki[y]=='-')){
					y--;					
				}

				else{
					

				}*/

				/*printf("%d\n",y);*/
				y1=y;

				i2=0;
				
				while(x!=y){
					sikia[i2]=p[x];
					i2++;
					x++;
				}
				sikia[i2]='\0';
				/*printf("%s☆\n",sikia);*/

				i3=0;
				while(sikia[i3]!='\0'){
					if((sikia[i3]=='+')||(sikia[i3]=='-')){
						absu(sikia,i3,sikia);
						break;
					}
					i3++;
				}


				/*printf("%s\n",sikia);*/
				strcpy(sikiA,p);

				c=0;
				while(sikia[c]!='\0'){
					sikiA[xa]=sikia[c];
					c++;
					xa++;
				}
				while(p[y1]!='\0'){
					sikiA[xa]=p[y1];
					y1++;
					xa++;
				}/*
				while(siki){
					sikiA[xa]=*/
				sikiA[xa]='\0';
				p[0]='\0';
				strcpy(p,sikiA);
				/*printf("%s\n",siki);*/
				/*printf("%d\n",aaa);*/
				/*printf("%s\n",p);*/
				break;
			}

			else{
				i++;
			}

		}
		jud2++;
	}
/*printf("括弧の式%s\n",p);*/



	c=0;
	while(c!=a){
		siki2[c]=siki[c];
		c++;
	}
	d=0;
	while(p[d]!='\0'){
		siki2[c]=p[d];
		d++;
		c++;
	}
	b++;
	for(e=b;siki[e]!='\0';e++){
		siki2[c]=siki[e];
		c++;
	}
	siki2[c]='\0';
	siki[0]='\0';
	strcpy(siki,siki2);

	jud++;
	}

 printf("括弧の式%s\n",siki);
/*/////////////////////////////////////////////////////////////////*/


	sikia[0]='\0';

	sikiA[0]='\0';

	sikiB[0]='\0';


	i=0;

	aaa=0;
	counta=0;
	countb=0;
	bbb=0;
	jud1=0;
	jud2=0;

		while(siki[counta]!='\0'){
			if((siki[counta]=='*')||(siki[counta]=='/')){
				aaa++;
			}
			counta++;
		}
		while(siki[countb]!='\0'){
			if((siki[countb]=='+')||(siki[countb]=='-')){
				bbb++;
			}
			countb++;
		}

	while(jud1!=aaa){

		while(siki[i]!='\0'){
			if((siki[i]=='*')||(siki[i]=='/')){
				x=i;
				x--;
				y=i;
				y++;
				
				while(x!=0){
					if((siki[x]>='0')&&(siki[x]<='9')){
						x--;
					}
					else{
						break;
					}
				}


				if((siki[x]=='*')||(siki[x]=='/')||(siki[x]=='+')){
					x++;					
				}
				else if(siki[x]=='-'){
				}

				else{

				}

				/*printf("%d\n",x);*/	
				xa=x;



				while(siki[y]!='\0'){
					if((siki[y]>='0')&&(siki[y]<='9')){
						y++;
					}
					else{
						break;
					}
				}


				/*printf("%d\n",y);*/
				y1=y;
				sikia[0]='\0';
				i2=0;
				while(x!=y){
					sikia[i2]=siki[x];
					i2++;
					x++;
				}
				/*printf("%d%d\n",x,y);*/
				sikia[i2]='\0';
				/*printf("%s\n",sikia);*/
				

				i3=0;
				while(sikia[i3]!='\0'){
					if((sikia[i3]=='*')||(sikia[i3]=='/')){
						mad(sikia,i3,sikia);
						break;
					}
					i3++;
				}

		
				/*printf("%s●\n",sikia);*/
				strcpy(sikiA,siki);
				/*xa++;*/
				c=0;
				while(sikia[c]!='\0'){
					sikiA[xa]=sikia[c];
					c++;
					xa++;
				}
				while(siki[y1]!='\0'){
					sikiA[xa]=siki[y1];
					y1++;
					xa++;
				}
				sikiA[xa]='\0';
				siki[0]='\0';
				strcpy(siki,sikiA);
				/*printf("%s★\n",siki);*/
				/*printf("%d\n",aaa);*/
				break;
			}

			else{
				i++;
			}

		}
		jud1++;
	}







	sikiA[0]='\0';
	sikia[0]='\0';
	sikiB[0]='\0';


	i=0;
	ii=0;

	while(jud2!=bbb){

		while(siki[i]!='\0'){

			if(siki[ii]=='-'){
				i++;
				ii=-1;
				printf("%c\n",siki[ii]);
			}
			else if((siki[i]=='+')||(siki[i]=='-')){

				x=i;
				x--;
				xxx=x;
				y=i;
				y++;
				
				while(x!=0){
					if(siki[xxx]=='-'){
						x--;
					}
					else if((siki[x]>='0')&&(siki[x]<='9')){
						x--;

					}
					else{
						break;
					}
				}
				if((siki[x]=='*')||(siki[x]=='/')||(siki[x]=='+')||(siki[x]=='-')){
					x++;					
				}
				else if(siki[x]=='-'){
				}
				else{

				}


				/*printf("%d\n",x);*/		
				xa=x;
				yyy=y;
				while(siki[y]!='\0'){
					
					if(siki[yyy]=='-'){
						y++;
						yyy=NULL;
					}
					else if((siki[y]>='0')&&(siki[y]<='9')){
						y++;
					}
					else{
						break;
					}
				}

				/*printf("yは%c\n",siki[y]);*/


				y1=y;

				i2=0;
				
				while(x!=y){
					sikia[i2]=siki[x];
					i2++;
					x++;

				}
				sikia[i2]='\0';

				/*printf("しきだよ%s\n",sikia);*/
				i3=0;
				while(sikia[i3]!='\0'){
					if((sikia[i3]=='+')||(sikia[i3]=='-')){
						absu(sikia,i3,sikia);
						break;
					}
					i3++;
				}


				/*printf("%s\n",sikia);*/
				strcpy(sikiA,siki);
				/*xa++;*/
				c=0;
				while(sikia[c]!='\0'){
					sikiA[xa]=sikia[c];
					c++;
					xa++;
				}
				while(siki[y1]!='\0'){
					sikiA[xa]=siki[y1];
					y1++;
					xa++;
				}/*
				while(siki){
					sikiA[xa]=*/
				sikiA[xa]='\0';
				siki[0]='\0';
				strcpy(siki,sikiA);
				/*printf("%s★\n",siki);*/

				break;
			}

			else{
				i++;
			}

		}
		jud2++;
	}
	printf("%s\n",siki);

}

void absu(char *siki,int i,char *p)
{
	int x,y,Y,XX,YY,ans,iy,ix,iix;
	XX=0;
	YY=0;
	x=i;
	x--;
	y=i;
	y++;
	Y=y;
	iy=0;
	ix=0;
	printf("しき%s\n",siki);
	if(siki[y]=='-'){
		y++;
		iy=1;
	}
	while(x!=0){
		if((siki[x]>='0')&&(siki[x]<='9')){
			x--;
		}
		else{
			break;
		}
	}
	/*printf("%c\n",siki[x]);*/
 
	iix=x;
	if(siki[iix]=='-'){
		ix=1;
		x++;
	}

	while(siki[y]!='\0'){
		if((siki[y]>='0')&&(siki[y]<='9')){
			y++;
		}
		else{
			break;
		}
	}
	y--;
	/*printf("%c\n",siki[y]);*/
	while(x!=i){
		XX=XX*10+siki[x]-'0';
		x++;
	}
	printf("xの値%d\n",XX);

	if(ix==1){
		XX=XX*(-1);
	}


	y++;
	Y++;

	while(Y!=y){
		YY=YY*10+siki[Y]-'0';
		Y++;
	}
	if(iy==1){
		YY=YY*(-1);
	}
	printf("yの値%d\n",YY);
	if(siki[i]=='+'){
	ans=XX+YY;
 
	}
	else{
		ans=XX-YY;
	}
	/*printf("%d\n",ans);*/
	p=itoa(ans,siki,10);
 
}

void mad(char *siki,int i,char *p)
{
	int x,y,Y,XX,YY,ans,iy,iix,ix;
	iy=0;
	XX=0;
	YY=0;
	x=i;
	x--;
	y=i;
	y++;
	Y=y;
	ix=0;
	/*printf("しき%s\n",siki);*/
	if(siki[y]=='-'){
		y++;
		iy=1;
	}
	while(x!=0){
		if((siki[x]>='0')&&(siki[x]<='9')){
			x--;
		}
		else{
			break;
		}
	}

	iix=x;
	if(siki[iix]=='-'){
		ix=1;
		x++;
	}
	

	while(siki[y]!='\0'){
		if((siki[y]>='0')&&(siki[y]<='9')){
			y++;
		}
		else{
			break;
		}
	}

	y--;
	/*printf("%c★\n",siki[y]);*/
	while(x!=i){
		XX=XX*10+siki[x]-'0';
		x++;
	}
	/*printf("%d(xの値)\n",XX);*/


	if(ix==1){
		XX=XX*(-1);
	}


	y++;
	while(Y!=y){

		YY=YY*10+siki[Y]-'0';
		Y++;
	}
	if(iy==1){
		YY=YY*(-1);
	}

	/*printf("%d(yの値)\n",YY);*/
	if(siki[i]=='*'){
	ans=XX*YY;
 
	}
	else{
		if(YY==0){

			printf("ゼロ除算は禁止されています\n");
			exit(1);
		}
		ans=XX/YY;
	}
	/*printf("%d\n",ans);*/
	p=itoa(ans,siki,10);
 
}