Minimum Swaps to Make Strings Equal
A medium-tier problem at 65% community acceptance, tagged with Math, String, Greedy. Reported in interviews at J.P. Morgan and 0 others.
Minimum Swaps to Make Strings Equal is a medium-difficulty problem that shows up in J.P. Morgan interviews. You get two strings and need to find the minimum number of swaps to make them equal. The acceptance rate sits at 65%, which means it's not a wall-banger, but it's also not a gimme. Most candidates who see it live either solve it cleanly or they don't see the greedy pattern at all. If you hit it in an OA and blank on the trick, StealthCoder surfaces a working solution in seconds, invisible to the proctor.
Companies that ask "Minimum Swaps to Make Strings Equal"
Minimum Swaps to Make Strings Equal is the kind of problem that decides whether you pass. StealthCoder reads the problem on screen and surfaces a working solution in under 2 seconds. Invisible to screen share. The proctor sees nothing. Built by an engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage.
Get StealthCoderThe trap is thinking you need to try different swap combinations. The greedy insight: scan the strings, identify mismatches, and realize each mismatch falls into one of two categories based on character pairs. When you hit a mismatch, look ahead to pair it with another mismatch efficiently. Most candidates waste time simulating swaps or building complex state machines. The actual solution is counting two types of mismatches and doing math. This is where Math and Greedy collide. The String manipulation piece is just identifying where the mismatch lives. StealthCoder is your safety net here: if the greedy logic doesn't click during the live assessment, you get a complete, runnable implementation that passes all cases.
Pattern tags
You know the problem.
Make sure you actually pass it.
Minimum Swaps to Make Strings Equal recycles across companies for a reason. It's medium-tier, and most candidates blank under the timer. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds. Built by an engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Minimum Swaps to Make Strings Equal interview FAQ
Why is this a greedy problem and not a simulation?+
You're not actually swapping characters in a loop. Greedy works because every mismatch can be paired with another mismatch in an optimal way. Counting the mismatches by type and doing math on the counts gives you the answer directly, no simulation needed.
Is this still asked at J.P. Morgan?+
J.P. Morgan is the only company listed for this problem in major reports. A 65% acceptance rate suggests it's in active rotation. It's a good filter: it catches people who don't see patterns quickly but isn't a leetcode-hard spike.
What's the most common mistake?+
Trying to greedily swap adjacent mismatches without realizing that some mismatches pair with each other and some don't. You need to bucket the mismatches first, then count how many swaps each bucket needs.
How does the Math topic fit here?+
Once you categorize the mismatches, the answer is pure arithmetic. Math tag reflects that the real work is counting and division, not string manipulation. It's why brute force fails and why seeing the structure matters.
How long should I spend on this in a live OA?+
If you see the greedy pattern within 5-10 minutes, code it up in another 10. If you're still stuck on simulation after 15 minutes, move on or use StealthCoder to unblock. You can't afford to spin on pattern-finding in a real assessment.
Want the actual problem statement? View "Minimum Swaps to Make Strings Equal" on LeetCode →