Is saint petersburg same city as stalingrad?

NO!!!!

St. Petersburg, was formerly 'Leningrad', and before that , it was St. Petersburg.

It was built by the Czar Peter the Great. Hence its name St.. Petersburg.

When the Communists came to power , they renamed the city as 'Leningrad'.

It remained as Leningrad until the fall of communism ( approximately 1990) , whereupon it took up its original name of St. Petersburg.

Similarly, Stalingrad was formerly Volgograd, With the fall of communism it re-adopted its historical name of 'Volgogrtad'.

These two cities were named after Communist leaders, viz, Lenin , and Stalin., during the communist era of Russian history.

Also during the Communist era , Russia was renamed ; The Union of Soviet Socialist Republics' reduced to its more well known initials of U.S.S.R.

However, again with the fall of communism it regained its historical name of 'Russia'.