示例题目。

1001/main.cpp

@@ -0,0 +1,71 @@
+#include <stdio.h>
+
+int main() {
+    char a[1000] = {0};
+    char b[1000] = {0};
+    char result[1001] = {0};
+    int a_index = 0, b_index = 0;
+    int result_index = 0;
+    char ch = getchar();
+    while (ch != ' ') {
+        a[a_index] = ch - '0';
+        ch = getchar();
+        a_index++;
+    }
+
+    a_index--;
+
+    ch = getchar();
+    while (ch != '\n' && ch != EOF && ch != ' ') {
+        b[b_index] = ch - '0';
+        ch = getchar();
+        b_index++;
+    }
+
+    b_index--;
+
+    if (a_index >= b_index) {
+        while (a_index >= 0) {
+            int current_digit = a[a_index] + b[b_index] + result[result_index];
+            result[result_index] = current_digit % 10;
+            result[++result_index] = current_digit / 10;
+            a_index--;
+            b_index--;
+        }
+
+        while (a_index >= 0) {
+            int current_digit = a[a_index] + result[result_index];
+            result[result_index] = current_digit % 10;
+            result[++result_index] = current_digit / 10;
+            a_index--;
+        }
+    }
+    else {
+        while (a_index >= 0) {
+            int current_digit = a[a_index] + b[b_index] + result[result_index];
+            result[result_index] = current_digit % 10;
+            result[++result_index] = current_digit / 10;
+            a_index--;
+            b_index--;
+        }
+
+        while (b_index >= 0) {
+            int current_digit = b[b_index] + result[result_index];
+            result[result_index] = current_digit % 10;
+            result[++result_index] = current_digit / 10;
+            b_index--;
+        }
+    }
+
+    if (result[result_index] == 0) {
+        // The hightest digit is carry. There is a possibility that this digit is 0.
+        result_index--;
+    }
+
+    while (result_index >= 0) {
+        printf("%d", result[result_index]);
+        result_index--;
+    }
+
+    return 0;
+}