下面程序main(){char a[]="ABCDEFG", k, *p;fun(a, 0, 2); fun(a, 4, 6);printf("%s\n", a);}fun(char *s, int p1, int p2){char c;while(p1<p2){c=s[p1]; s[p1]=s[p2];s[p2]=c; p1++; p2--;}}输出结果是( )
A.ABCDEFG
B.DEFGABC
C.GFEDCBA
D.CBADGFE

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