Compilare: user.cpp: In function 'int main()': user.cpp:20: warning: conversion lacks type at end of format user.cpp:20: warning: too many arguments for format user.cpp:21: warning: conversion lacks type at end of format user.cpp:21: warning: conversion lacks type at end of format user.cpp:21: warning: too many arguments for format user.cpp:37: warning: conversion lacks type at end of format user.cpp:37: warning: too many arguments for format