300.最长递增子序列
从前往后遍历即可
cpp
class Solution {
public:
int lengthOfLIS(vector<int>& nums) {
if (nums.size() <= 1) return nums.size();
vector<int> dp(nums.size(), 1);
int result = 0;
for (int i = 1; i < nums.size(); i++) {
for (int j = 0; j < i; j++) {
if (nums[i] > nums[j]) dp[i] = max(dp[j] + 1, dp[i]);
}
if (dp[i] > result) result = dp[i];
}
return result;
}
};
674. 最长连续递增序列
DP
cpp
class Solution {
public:
int findLengthOfLCIS(vector<int>& nums) {
if (nums.size() == 0) return 0;
int result = 1;
vector<int> dp(nums.size(), 1);
for (int i = 1; i < nums.size(); i++) {
if (nums[i] > nums[i - 1]) {
dp[i] = dp[i - 1] + 1;
}
if (dp[i] > result) result = dp[i];
}
return result;
}
};
贪心
cpp
class Solution {
public:
int findLengthOfLCIS(vector<int>& nums) {
if (nums.size() == 0) return 0;
int result = 1;
int count = 1;
for (int i = 1; i < nums.size(); i++) {
if (nums[i] > nums[i - 1]) {
count++;
} else {
count = 1;
}
if (count > result) result = count;
}
return result;
}
};
718. 最长重复子数组
nums1和nums2匹配上之后,dp数组状态只能由其左上角推出来
cpp
class Solution {
public:
int findLength(vector<int>& nums1, vector<int>& nums2) {
vector<vector<int>> dp(nums1.size() + 1, vector<int>(nums2.size() + 1, 0));
int result = 0;
for (int i = 1; i <= nums1.size(); i++) {
for (int j = 1; j <= nums2.size(); j++) {
if (nums1[i - 1] == nums2[j - 1]) {
dp[i][j] = dp[i - 1][j - 1] + 1;
}
if (dp[i][j] > result) result = dp[i][j];
}
}
return result;
}
};