matrice4.cpp: In function 'int main()': matrice4.cpp:11: warning: unused variable 'l' matrice4.cpp:13: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result matrice4.cpp:18: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result matrice4.cpp:11: warning: 'j' may be used uninitialized in this function matrice4.cpp:11: warning: 'mr' may be used uninitialized in this function