LeetCode 416 Partition Equal Subset Sum - Walkthrough

Trace Partition Equal Subset Sum on $[1, 5, 11, 5]$. Total sum is $22$, so we need a subset summing to $11$. Build $dp[s]$ = true if sum $s$ is achievable. Start with $dp[0] = true$.

After $1$: $dp[1] = true$. After $5$: $dp[5] = true$, $dp[6] = true$. After $11$: $dp[11] = true$, $dp[16] = true$, $dp[17] = true$. After second $5$: $dp[10] = true$, $dp[11]$ already true. Since $dp[11] = true$, the answer is YES. The subset $\{5, 5, 1\}$ or $\{11\}$ works.