Conversão char para int.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(){
    char x[10]={0};
    int i, j=0, X;

    printf("\n Insira n%cmeros = ",163);
    scanf("%s", x);
    for(i=0;i!='\0';i++){
        switch(x[i]){
            case 48:j++;
                break;
            case 49:j++;
                break;
            case 50:j++;
                break;
            case 51:j++;
                break;
            case 52:j++;
                break;
            case 53:j++;
                break;
            case 54:j++;
                break;
            case 55:j++;
                break;
            case 56:j++;
                break;
            case 57:j++;
                break;
        }
    }
    if(j<=i){
        X=atoi(x);
        printf("\t%d", X);
    }
    return 0;
}