題目：https://www.patest.cn/contests/pat-a-PRactise/1024

代碼：

#include <stdio.h>#include <string.h>#include <algorithm>using namespace std;struct bign {    int d[1000];    int len;    bign() {        memset(d, 0, sizeof(d));        len = 0;    }};bign change(char str[]) {    bign a;    a.len = strlen(str);    for(int i = 0; i < a.len; i++) {        a.d[i] = str[a.len - i - 1] - '0';    }    return a;}bign add(bign a, bign b) {    bign c;    int carry = 0;    for(int i = 0; i < a.len || i < b.len; i++) {        int temp = a.d[i] + b.d[i] + carry;        c.d[c.len++] = temp % 10;        carry = temp / 10;    }    if(carry != 0) {        c.d[c.len++] = carry;    }    return c;}bool Judge(bign a) {    for(int i = 0; i <= a.len / 2; i++) {        if(a.d[i] != a.d[a.len - 1 - i]) {            return false;        }    }    return true;}void print(bign a) {    for(int i = a.len - 1; i >= 0; i--) {        printf("%d", a.d[i]);    }    printf("/n");}int main() {    char str[1000];    int T, k = 0;    scanf("%s %d", str, &T);    bign a = change(str);    while(k < T && Judge(a) == false) {        bign b = a;        reverse(b.d, b.d + b.len);        a = add(a, b);        k++;    }    print(a);    printf("%d/n", k);    return 0;}