2809. 使数组和小于等于 x 的最少时间

 2809. 使数组和小于等于 x 的最少时间 - 力扣（LeetCode）https://leetcode.cn/problems/minimum-time-to-make-array-sum-at-most-x/?envType=daily-question&envId=2024-01-19

 经典动态规划

class Solution {
public:
    int minimumTime(vector& nums1, vector& nums2, int x) {
        int n = nums1.size();
        vector ind(n);
        iota(ind.begin(), ind.end(), 0);
        sort(ind.begin(), ind.end(), [&](int i, int j) {
            return nums2[i] < nums2[j];
        });
        vector f(n + 1);
        //f[i]:前n个数操作i次最大减少量
        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j > 0; j--) {
                f[j] = max(f[j], f[j - 1] + nums1[ind[i]] + nums2[ind[i]] * j);
            }
        }   
        int s1 = accumulate(nums1.begin(), nums1.end(), 0);
        int s2 = accumulate(nums2.begin(), nums2.end(), 0);
        for (int i = 0; i <= n; i++) {
            if (s1 + i * s2 - f[i] <= x) {
                return i;
            }
        }
        return -1;
    }
};