题意:输入C,找出A,B使得A,B的各个位数字和最大。
#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include<iostream>
#include<math.h>
#include<queue>
#include<stack>
#include<cstring>
#include<string>
//#include<map>
typedef long long LL;
using namespace std;
int a, b, c;
int fun(int num) {
int add = 0;
while (num > 0) {
add += num % 10;
num /= 10;
}
return add;
}
int main()
{
int NUM = 10;
while (1) {
int maxsum = 0, maxa, maxb;
for (int i = 1; i < NUM/2; i++) {
int j = NUM - i;
if (fun(j) + fun(i) > maxsum) {
maxsum = fun(j) + fun(i);
maxa = i;
maxb = j;
}
}
cout << maxa <<" "<< maxb <<" "<< maxsum << endl;
NUM++;
}
}
打表发现A和B其中一个数是由n个9组成的,所以只要找到小于C且由n个9组成的最大的数就行了。
#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include<iostream>
#include<math.h>
#include<queue>
#include<stack>
#include<cstring>
#include<string>
//#include<map>
typedef long long LL;
using namespace std;
LL c, a, b;
LL S(LL num) {
int sum = 0;
while (num>0) {
sum += num % 10;
num /= 10;
}
return sum;
}
int main() {
cin >> c;
if (c < 10) {
cout << c;
return 0;
}
a = 9;
while (a < c) {
a *= 10; a += 9;
}
a /= 10;
b = c - a;
cout << S(a) + S(b);
}