正确格式为%lf,scanf("%lf",double type variable);
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┌────────────────────────────────────────┐
│ ...scanf Format Specifiers │
├────────────────────────────────────────┤
│In ...scanf format strings, format specifiers have the following form: │
│ │
│ % [ * ] [width] [F|N] [h|l|L] pe_char │
│ │
│Each format specifier begins with the percent character (%). │
│ │
│After the % come the following, in this order: │
│ │
│┌─────┬────────────────────────────────┐│
││Component │What It Is/Does ││
│├─────┼────────────────────────────────┤│
││ [ * ] │(Optional) Assignment-suppression character ││
││ │Suppresses assignment of the next input field. ││
││ [width] │(Optional) Width specifier ││
││ │Specifies maximum number of characters to read; fewer ││
││ │characters might be read if the ...scanf function encounters ││
││ │a whitespace or unconvertible character. ││
││ [F|N] │(Optional) Pointer size modifier ││
││ │Overrides default size of address argument: ││
││ │ N = near pointer ││
││ │ F = far pointer ││
││ [h|l|L] │(Optional) Argument-type modifier ││
││ │Overrides default type of address argument: ││
││ │ h = short int ││
││ │ l = long int, if type_char specifies integer conversion ││
││ │ l = double, if type_char specifies floating-point conversion ││
││ │ L = long double, (valid only with floating-point conversion) ││
││ type_char│(Required) Type character ││
│└─────┴────────────────────────────────┘│
└────────────────────────────────────────┘