Perhaps you should try some spelling variations:
"coder coder sequence tree problem" » "coder order sequence tree problem" (Expand search), "coder under sequence tree problem" (Expand search), "coder leader sequence tree problem" (Expand search), "coder coder sequence trace problem" (Expand search), "coder coder sequence type problem" (Expand search), "coder coder sequence the problem" (Expand search), "coder decoder sequence tree problem" (Expand search), "code code sequence tree problem" (Expand search), "decoder codec sequence tree problem" (Expand search)
"api python python python programming" » "api pythons python python programming" (Expand search), "api piton python python programming" (Expand search), "api pitons python python programming" (Expand search)

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("coder coder sequence tree problem") OR ("api python python python programming"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"coder coder sequence tree problem\") OR (\"api python python python programming\"))".
• Removing quotes may allow a broader search: (( coder coder sequence tree problem ) OR ( api python python python programming )).
• Adding a wildcard symbol may retrieve word variants: (("coder coder sequence tree problem") OR ("api python python python programming"))*.