feat: add typescript solution to lc problem: No.1737 (#650)

No.1737.Change Minimum Characters to Satisfy One of Three Conditions

Author: zhaocchen

solution/1700-1799/1737.Change Minimum Characters to Satisfy One of Three Conditions/README.md

@@ -50,6 +50,7 @@
 ## 解法
 
 <!-- 这里可写通用的实现逻辑 -->
+前缀和
 
 <!-- tabs:start -->
 
@@ -69,6 +70,36 @@
 
 ```
 
+### **TypeScript**
+
+```ts
+function minCharacters(a: string, b: string): number {
+    const m = a.length, n = b.length;
+    let count1 = new Array(26).fill(0);
+    let count2 = new Array(26).fill(0);
+    const base = 'a'.charCodeAt(0);
+
+    for (let char of a) {
+        count1[char.charCodeAt(0) - base]++;
+    }
+    for (let char of b) {
+        count2[char.charCodeAt(0) - base]++;
+    }
+    
+    let pre1 = 0, pre2 = 0;
+    let ans = m + n;
+    for (let i = 0; i < 25; i++) {
+        pre1 += count1[i];
+        pre2 += count2[i];
+        // case1， case2， case3
+        ans = Math.min(ans, m - pre1 + pre2, pre1 + n - pre2, m + n - count1[i] - count2[i]);
+    }
+    ans = Math.min(ans, m + n - count1[25] - count2[25]);
+    
+    return ans;
+};
+```
+
 ### **...**
 
 ```

solution/1700-1799/1737.Change Minimum Characters to Satisfy One of Three Conditions/README_EN.md

@@ -47,6 +47,8 @@ The best way was done in 2 operations (either condition 1 or condition 3).
 
 ## Solutions
 
+Prefix Sum
+
 <!-- tabs:start -->
 
 ### **Python3**
@@ -61,6 +63,36 @@ The best way was done in 2 operations (either condition 1 or condition 3).
 
 ```
 
+### **TypeScript**
+
+```ts
+function minCharacters(a: string, b: string): number {
+    const m = a.length, n = b.length;
+    let count1 = new Array(26).fill(0);
+    let count2 = new Array(26).fill(0);
+    const base = 'a'.charCodeAt(0);
+
+    for (let char of a) {
+        count1[char.charCodeAt(0) - base]++;
+    }
+    for (let char of b) {
+        count2[char.charCodeAt(0) - base]++;
+    }
+    
+    let pre1 = 0, pre2 = 0;
+    let ans = m + n;
+    for (let i = 0; i < 25; i++) {
+        pre1 += count1[i];
+        pre2 += count2[i];
+        // case1， case2， case3
+        ans = Math.min(ans, m - pre1 + pre2, pre1 + n - pre2, m + n - count1[i] - count2[i]);
+    }
+    ans = Math.min(ans, m + n - count1[25] - count2[25]);
+    
+    return ans;
+};
+```
+
 ### **...**
 
 ```

solution/1700-1799/1737.Change Minimum Characters to Satisfy One of Three Conditions/Solution.ts

@@ -0,0 +1,25 @@
+function minCharacters(a: string, b: string): number {
+    const m = a.length, n = b.length;
+    let count1 = new Array(26).fill(0);
+    let count2 = new Array(26).fill(0);
+    const base = 'a'.charCodeAt(0);
+
+    for (let char of a) {
+        count1[char.charCodeAt(0) - base]++;
+    }
+    for (let char of b) {
+        count2[char.charCodeAt(0) - base]++;
+    }
+    
+    let pre1 = 0, pre2 = 0;
+    let ans = m + n;
+    for (let i = 0; i < 25; i++) {
+        pre1 += count1[i];
+        pre2 += count2[i];
+        // case1， case2， case3
+        ans = Math.min(ans, m - pre1 + pre2, pre1 + n - pre2, m + n - count1[i] - count2[i]);
+    }
+    ans = Math.min(ans, m + n - count1[25] - count2[25]);
+    
+    return ans;
+};