- 115 名前：デフォルトの名無しさん mailto:sage [2009/02/01(日) 22:40:06 ]
- >>112 括弧を対応させる方法が思い出せない
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
char b[256], *p = b;
double t(void){
double t = 0;
while(1){
if(isspace(*p)) p++;
else if(*p == '*'){ p++; t *= strtol(p, &p, 10);}
else if(*p == '/'){ p++; t /= strtol(p, &p, 10);}
else if(isdigit(*p)) t = strtol(p, &p, 10);
else return t;
}
}
double e(double r){
while(1){
if(isspace(*p)) p++;
else if(*p == '\0') return r;
else if(*p == '+'){ p++; r += t();}
else if(*p == '-'){ p++; r -= t();}
else r = t();
}
}
int main(int c, char *v[]){
FILE *in, *out;
if(c < 3 || (in = fopen(v[1], "r")) == NULL ||
(out = fopen(v[2], "w")) == NULL) return 1;
fscanf(in, "%255[^\n]", b);
fprintf(out, "%g\n", e(t()));
return fclose(in), fclose(out), 0;
}
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