Iowa State basketball coach Larry Eustachy resigned yesterday. The move came a week after pictures of him drinking and kissing girls on the cheek at a college party in Columbia were published in the Des Moines Register. Last Wednesday, Eustachy admitted that he had a drinking problem and was seeking treatment. On the same day Athletic Director Bruce Van De Veld suggested that he be fired. Eustachy went to the party after Iowa State lost to Missouri 64-59 on January 21 at the Hearnes Center.