#shortest path

15 shortest path interview questions, asked at Uber, Microsoft, Google and 7 more companies. Last asked Sep 2026.

Shortest path through a digit grid with diagonal movesCodingYou are given an m x n grid of digits. A cell holding 0 is a wall; a cell holding 1 through 9 is open. Starting at the top-left cell (0, 0), find a shortest route to the…
Last asked Sep 2026
Cell with the least total walking distance to all targets around wallsCodingA grid has targets, empty cells and walls. Walking moves up, down, left or right and cannot cross walls. Find a non-wall cell whose summed walking distance to every target is as…
Last asked Sep 2026
Fastest single-mode commute on a city gridCodingYou are planning a commute across a city drawn as a 2D grid of characters: - 'S': your starting point (exactly one). - 'D': your destination (exactly one). - '1' to 'k': a block…
Last asked Sep 2026
Shortest path in a grid with obstacle eliminationCodingA grid has empty cells and obstacles. Find the fewest steps from the top-left to the bottom-right cell moving up, down, left or right, when you may remove up to k obstacles along…
Last asked Aug 2026
Robot route with charging cells: fewest charges, then battery, then movesCodingA robot crosses a grid from S to D. Cells are . (open), (blocked) or C (a charging cell). The battery limits how far the robot can go between charges, and a charging cell refills…
Last asked Aug 2026
Fewest road reversals in a directed networkCodingA road network has one-way roads. Travelling a road against its direction counts as a violation. Find a route between two given cities with as few violations as possible.
Last asked Jul 2026
Shortest path in a grid with blocked cellsCodingGiven a grid in which some cells are blocked, return the length of the shortest path from a start cell to a target cell, moving up, down, left or right, or report that no path…
Last asked Jun 2026
Fewest moves across a grid when each move can jump up to k cellsCodingOn a grid with blocked cells, each move goes up, down, left or right by one to k cells, without passing through a blocked cell. Return the fewest moves from the start to the…
Last asked Jun 2026
Shortest travel times from a start node to target nodesCodingA weighted graph models a road map. Given a start node and one or more target nodes, return the shortest travel time (an ETA) from the start to each target. Use Dijkstra's…
Last asked Apr 2026
Shortest cycle through each nodeCodingIn a weighted graph, find for every node the cost of the cheapest cycle that passes through it, or report that none exists. Only the title of this report was public; discuss the…
Last asked Feb 2026
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Cheapest flights within K stopsCodingGiven flights as (from, to, price), a source, a destination and an integer k, return the cheapest price from the source to the destination using at most k stops, or -1 if there is…
Last asked Feb 2026
Shortest path in a grid with obstaclesCodingGiven a 2D grid where some cells are blocked, find the length of the shortest path from the top-left cell to the bottom-right cell moving up, down, left or right, or return -1 if…
Last asked Dec 2025
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Best currency conversion rate across exchange quotesCodingYou run a currency desk. You are given a list of quotes (from, to, rate): one unit of from buys rate units of to. A quote works only in the direction given; the reverse is…
Last asked Nov 2025
Budget queries on a sorted price list, then a shortest pathCodingTwo problems in a 90-minute assessment. First, items come sorted by price; for each budget query, return how many items you can buy. A knapsack DP is too slow; prefix sums with…
Last asked Aug 2025
Reachable sum with reusable values and a huge targetCodingGiven a non-empty list nums of positive integers and a target k, return true if some multiset of values from nums sums to exactly k, and false otherwise. You may use each value…