c语言输入三个分数，并进行按从高到低等级进行排序，再输出结果

#include <stdio.h>

float a,b,c;

void sortabc();

void putabc();

char grade(float x);

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

{

float a,b,c;

scanf("%f,%f,%f",&a,&b,&c);

sortabc();

grade(a);

putabc();

}

void sortabc()

{

float t;

if(a<b)

{t=a;a=b;b=t;}

if(b<c)

{t=b;c=b;c=t;}

if (a<b)

{t=a;a=b;b=t;}

}

char grade(float x)

{

if(x>=85)

return ('A');

else

if (x>70)

{

return ('B');

}

else

if (x>=60)

{

return ('c');

}

else

return ('D');

}

void putabc()

{

char g;

g=grade(a);

printf("%6.1f:%c",a,g);

g=grade(b);

printf("%6.1f:%c",b,g);

g=grade(c);

printf("%6.1f:%c",c,g);

}