宏定义:#define SQR(X) X*X,因为X*X没有加括号,直接替换:
SQR(k+m)=k+m*k+m
SQR(k+m)/SQR(k+m)=k+m*k+m/k+m*k+m
a/=SQR(k+m)/SQR(k+m)替换为:a/=k+m*k+m/k+m*k+m
此时:a=10,k=2,m=1;
即a/=2+1*2+1/2+1*2+1
a为int,故1/2=0, 即a/=7
所以最后a=10/7=1
关键是a/=SQR(k+m)/SQR(k+m);这句展开后是:
a/=k+m*k+m/k+m*k+m
即 a=a/(4+1/2+3)=10/7=1