#include <stdio.h>
#include <math.h>

int main(){
    float x=1.0;
    float toosmall=0;
    float toolarge=x;
    float oldaverage=0;
    for(int n=0;;n++){
        float average=(toosmall+toolarge)/2;
        printf("Guess %d is %.17g\n",n+1,average);
        float xnew=x+average;
        if(xnew==x){
            printf("\tWhich is too small!\n");
            toosmall=average;
        } else {
            printf("\tWhich is too large!\n");
            toolarge=average;
        }
        if(oldaverage==average) break;
        oldaverage=average;
    }
    printf("The largest epsilon such that x+epsilon=x\n");
    printf("is %.17g\n",toosmall);
    return 0;
}