Getting a Wrong Answer (WA) on Codeforces doesn't always mean your algorithm is wrong. Sometimes, small implementation mistakes are the real problem.↵
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Here are 6 common mistakes to watch out for when coding in C.↵
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1. Integer Overflow↵
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Using "int" for values that exceed its range can produce incorrect results. Use "long long" when necessary.↵
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2. Wrong Format Specifiers↵
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Match your format specifiers with the data types.↵
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- "int" → "%d"↵
- "long long" → "%lld"↵
- "double" in "scanf()" → "%lf"↵
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3. Output Formatting↵
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Extra spaces, missing newlines, or unnecessary messages can cause WA. Follow the exact output format.↵
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4. Integer Division↵
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In C, "5 / 2" produces "2", not "2.5". Use floating-point arithmetic when decimals are required.↵
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5. Boundary Cases↵
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Don't test only ordinary inputs. Check minimum values, maximum values, zero, and other special cases allowed by the constraints.↵
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6. Incorrect "scanf()" Usage↵
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Remember the address operator ("&") when reading variables.↵
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scanf("%d", &a); // Correct↵
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Before Submitting↵
↵
- Check constraints and data types.↵
- Verify format specifiers.↵
- Check output formatting.↵
- Test boundary cases.↵
- Double-check input statements.↵
↵
Remember: A small bug can cause a Wrong Answer. Learn to identify the mistake, understand it, and avoid repeating it.↵
↵
Happy coding!
↵
Here are 6 common mistakes to watch out for when coding in C.↵
↵
1. Integer Overflow↵
↵
Using "int" for values that exceed its range can produce incorrect results. Use "long long" when necessary.↵
↵
2. Wrong Format Specifiers↵
↵
Match your format specifiers with the data types.↵
↵
- "int" → "%d"↵
- "long long" → "%lld"↵
- "double" in "scanf()" → "%lf"↵
↵
3. Output Formatting↵
↵
Extra spaces, missing newlines, or unnecessary messages can cause WA. Follow the exact output format.↵
↵
4. Integer Division↵
↵
In C, "5 / 2" produces "2", not "2.5". Use floating-point arithmetic when decimals are required.↵
↵
5. Boundary Cases↵
↵
Don't test only ordinary inputs. Check minimum values, maximum values, zero, and other special cases allowed by the constraints.↵
↵
6. Incorrect "scanf()" Usage↵
↵
Remember the address operator ("&") when reading variables.↵
↵
scanf("%d", &a); // Correct↵
↵
Before Submitting↵
↵
- Check constraints and data types.↵
- Verify format specifiers.↵
- Check output formatting.↵
- Test boundary cases.↵
- Double-check input statements.↵
↵
Remember: A small bug can cause a Wrong Answer. Learn to identify the mistake, understand it, and avoid repeating it.↵
↵
Happy coding!
