"Algorithmic Competition Primer Classic Second Edition" P35 exercise 2-4 sub-sequence and (subsequence)

/*"Algorithmic Competition Primer Classic Second Edition" P35 exercise 2-4; Enter two positive integers n < m < 10^6, output (1/n) ^2 + 1/(n+1) ^2 +......+ 1/m^2, retain 5 decimal places.  The input contains multiple sets of data, and the end flag is m=n=0. Wrong welcome to point out ^_^*/#include<stdio.h>intMain () {intm,n,i,j=1;  while(SCANF ("%d%d", &m,&n)! =EOF) {        Doublesum =0; if(m==0&& n==0)             return 0; Else        {             for(i=m; i<=n; i++) {sum+= ((1.0/i) * (1.0/i));//Fractional Arithmetic writes a numerator or denominator to a floating-point type, allowing it to automatically convert to decimals. } printf ("Case %d:%.5f\n", j,sum); J++; }    }    return 0;}

"Algorithmic Competition Primer Classic Second Edition" P35 exercise 2-4 sub-sequence and (subsequence)