>>156
#include <stdio.h>
#include <assert.h>
#include <math.h>
#include <string.h>
#define func(x) (exp(-pow((x),2))-sin(x))
int main(int argc, char **argv) {
double low=0, mid, high=1, ret;
double e = 5 * pow(10,-7);
int count = 0;

assert((func(low)<0&&func(high)>0) || (func(low)>0&&func(high)<0));
for (;;) {
count++;
mid=(low+high)/2;
if (fabs(ret=func(mid))<e)
break;
if (ret>0)
low = mid;
else
high = mid;
}
if (argc==2 && strcmp(argv[1],"-k")==0)
printf("%d times, ans: %f\n",count,mid);
else
printf("ans: %f\n",mid);
return 0;
}
完全に仕様には沿ってないけど、こんなもんでどう？