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0_0_28455736_32087.cpp: In function 'double slop(int, int)':
0_0_28455736_32087.cpp:10:28: error: 's' was not declared in this scope
  return double(dp[i]-dp[j]+s[i]*s[i]-s[j]*s[j])/double(2*(s[i]-s[j]));  //注意'2'  !!移项了     与ppt中不同为：(dp[i]-dp[j]+s[i]*s[i]-s[j]*s[j])/(2*(s[i]-s[j]) 
                            ^