Update 0416.分割等和子集.md about rust

去除不必要的方法

problems/0416.分割等和子集.md

@@ -406,24 +406,21 @@ var canPartition = function(nums) {
 
 ```Rust
 impl Solution {
-    fn max(a: usize, b: usize) -> usize {
-        if a > b { a } else { b }
-    }
     pub fn can_partition(nums: Vec<i32>) -> bool {
-        let nums = nums.iter().map(|x| *x as usize).collect::<Vec<usize>>();
-        let mut sum = 0;
-        let mut dp: Vec<usize> = vec![0; 10001];
-        for i in 0..nums.len() {
-            sum += nums[i];
+        let sum = nums.iter().sum::<i32>() as usize;
+        if sum % 2 == 1 {
+            return false;
         }
-        if sum % 2 == 1 { return false; }
         let target = sum / 2;
-        for i in 0..nums.len() {
-            for j in (nums[i]..=target).rev() {
-                dp[j] = Self::max(dp[j], dp[j - nums[i]] + nums[i]);
+        let mut dp = vec![0; target + 1];
+        for n in nums {
+            for j in (n as usize..=target).rev() {
+                dp[j] = dp[j].max(dp[j - n as usize] + n)
             }
         }
-        if dp[target] == target { return true; }
+        if dp[target] == target as i32 {
+            return true;
+        }
         false
     }
 }