leetcode

Daily Problem

4 files changed, 68 insertions(+), 46 deletions(-)

diff --git a/ 1639.cpp b/ 1639.cpp

@@ -1,46 +0,0 @@

// Concise way

class Solution {

long dp[1001] = {1, 0};

public:

int numWays(const vector<string> &words, const string &target) {

int n = target.length(), mod = 1e9 + 7;

for (int i = 0; i < words[0].length(); ++i) {

vector<int> count(26);

for (const auto &w : words) count[w[i] - 'a']++;

for (int j = n - 1; j >= 0; --j)

dp[j + 1] += (dp[j] * count[target[j] - 'a']) % mod;

}

return dp[n] % mod;

}

};

// Relatively dump way

class Solution {

int dp[1001][1001] = {0};

int count[1001][26] = {0};

int mod = 1E9 + 7;

int rec(const vector<string> &words, const string &target, int k = 0,

int l = 0) {

if (k >= target.size()) return 1;

if (l >= words[0].size()) return 0;

if (dp[k][l] != -1) return dp[k][l];

long long res = rec(words, target, k, l + 1);

res += ((long long)count[l][target[k] - 'a'] *

rec(words, target, k + 1, l + 1)) %

mod;

return dp[k][l] = res % mod;

}

public:

int numWays(const vector<string> &words, const string &target) {

memset(dp, 0xFF, 1001 * 1001 * sizeof(int)); // init dp to -1

for (int i = 0; i < words.size(); i++)

for (int j = 0; j < words[i].size(); j++) count[j][words[i][j] - 'a']++;

return rec(words, target, 0, 0);

}

};

diff --git a/ Problems/1456.cpp b/ Problems/1456.cpp

@@ -0,0 +1,21 @@

class Solution {

bool isVowel(char c) {

return c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u';

}

public:

int maxVowels(string s, int k) {

int i, cnt = 0;

for (i = 0; i < k; i++)

if (isVowel(s[i])) cnt++;

int maxi = cnt;

for (; i < s.size(); i++) {

if (isVowel(s[i - k])) cnt--;

if (isVowel(s[i])) cnt++;

maxi = max(maxi, cnt);

}

return maxi;

}

};

diff --git a/ Problems/1639.cpp b/ Problems/1639.cpp

@@ -0,0 +1,46 @@

// Concise way

class Solution {

long dp[1001] = {1, 0};

public:

int numWays(const vector<string> &words, const string &target) {

int n = target.length(), mod = 1e9 + 7;

for (int i = 0; i < words[0].length(); ++i) {

vector<int> count(26);

for (const auto &w : words) count[w[i] - 'a']++;

for (int j = n - 1; j >= 0; --j)

dp[j + 1] += (dp[j] * count[target[j] - 'a']) % mod;

}

return dp[n] % mod;

}

};

// Relatively dump way

class Solution {

int dp[1001][1001] = {0};

int count[1001][26] = {0};

int mod = 1E9 + 7;

int rec(const vector<string> &words, const string &target, int k = 0,

int l = 0) {

if (k >= target.size()) return 1;

if (l >= words[0].size()) return 0;

if (dp[k][l] != -1) return dp[k][l];

long long res = rec(words, target, k, l + 1);

res += ((long long)count[l][target[k] - 'a'] *

rec(words, target, k + 1, l + 1)) %

mod;

return dp[k][l] = res % mod;

}

public:

int numWays(const vector<string> &words, const string &target) {

memset(dp, 0xFF, 1001 * 1001 * sizeof(int)); // init dp to -1

for (int i = 0; i < words.size(); i++)

for (int j = 0; j < words[i].size(); j++) count[j][words[i][j] - 'a']++;

return rec(words, target, 0, 0);

}

};

diff --git a/ README.md b/ README.md

@@ -443,6 +443,7 @@ for solving problems. | 1438 | Medium | [Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit](Problems/1438.cpp) | | 1443 | Medium | [Minimum Time to Collect All Apples in a Tree](Problems/1443.cpp) | | 1444 | Hard | [Number of Ways of Cutting a Pizza](Problems/1444.cpp) |

| 1456 | Medium | [Maximum Number of Vowels in a Substring of Given Length](Problems/1456.cpp) |

| 1462 | Medium | [Course Schedule IV](Problems/1462.cpp) | | 1466 | Medium | [Reorder Routes to Make All Paths Lead to the City Zero](Problems/1466.cpp) | | 1470 | Easy | [Shuffle the Array](Problems/1470.cpp) |