simm.c

来自「足球机器人自动程序」· C语言 代码 · 共 43 行

#include <stdio.h>
#include <string.h>

union {
	int i;
	float f;
} fi;

int main(int argc, char *argv[]) {

	if (argc == 1) {
		fprintf(stderr, "Usage: %s n\n", argv[0]);
		return -1;
	}

	int i = 1;
	for (; i<argc; ++i) {

		if (sscanf(argv[i], "%f", &fi.f) != 1) {
			fprintf(stderr, "invalid input: %s\n", argv[i]);
			continue;
		}

		printf("%f = ", fi.f);

		int f = fi.i & 0x7fffff;
		int e = ((fi.i & 0x7f800000) >> 23) - 127;

		printf("2^%d", e);
		int b = 0x400000;
		int j = 0;
		for(; j<23; ++j) {
			--e;
			if (f & b) printf(" + 2^%d", e);
			b>>=1;
		}
		printf("\n");
	}

	return 0;
}