1.对于double类型,输入格式为scanf("%lf %lf", &foo, &bar);
对于float类型,输入格式为scanf("%f %f, &foo, &bar);
2.对于double类型和float类型,输出格式均为printf("%f %f\n", foo, bar);
1.对于double类型,输入格式为scanf("%lf %lf", &foo, &bar);
对于float类型,输入格式为scanf("%f %f, &foo, &bar);
2.对于double类型和float类型,输出格式均为printf("%f %f\n", foo, bar);