Given a non-empty array containing only positive integers, find if the array can be partitioned into two subsets such that the sum of elements in both subsets is equal.
Note:Each of the array element will not exceed 100.The array size will not exceed 200.Example 1:Input: [1, 5, 11, 5]Output: trueExplanation: The array can be partitioned as [1, 5, 5] and [11].Example 2:Input: [1, 2, 3, 5]Output: falseExplanation: The array cannot be partitioned into equal sum subsets.
01背包问题,v = sum(nums[i])/2那么原问题可以转换为将n个物品装入容量为v的背包中能得到的最大值。如果最大值为v那么就返回true否则返回false
class Solution {public: bool canPartition(vector & nums) { int n = nums.size(); int v = accumulate(nums.begin(), nums.end(), 0); if (v & 1) return false; v /= 2; vector dp(v+1); // dp[i][j] = max(dp[i-1][j],dp[i-1][j-a[i]] + w[i]); for (int i = 0; i < n; ++i) { for (int j = v; j >= nums[i]; --j) { dp[j] = max(dp[j-nums[i]] + nums[i], dp[j]); } } cout << dp[v] <