/in/foo.cc: In function 'double slope(int, int)':
/in/foo.cc:12:16: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
     return (f[r&1^1][k]-pow(sum[k])-f[r&1^1][j]+pow(sum[j]))*1.0/(sum[j]-sum[k]);
               ~^~
/in/foo.cc:12:40: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
     return (f[r&1^1][k]-pow(sum[k])-f[r&1^1][j]+pow(sum[j]))*1.0/(sum[j]-sum[k]);
                                       ~^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:24:26: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
             f[r&1][i]=f[r&1^1][q[h]]+sum[q[h]]*(sum[i]-sum[q[h]]);
                         ~^~