CF 118C
这个题目可以暴力枚举变成0~9的情况，但究竟优先变哪一个位置需要分情况进行讨论，因此可以先按优先级将位置进行排序，依次改变该位置上的数字即可。
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
int number, a[10010], b[11][10010], sum[11], r[10010];
char str[10010];
int cmp(const void *_p, const void *_q)
{
int *p = (int *)_p;
int *q = (int *)_q;
if(abs(a[*p] - number) == abs(a[*q] - number))
{
if(a[*p] == a[*q])
{
if(number > a[*p])
return *q - *p;
else
return *p - *q;
}
else
{
if(number < a[*p] && number < a[*q])
return *p - *q;
else if(number > a[*p] && number > a[*q])
return *q - *p;
else
{
if(a[*p] > a[*q])
return -1;
else
return 1;
}
}
}
else
return abs(a[*p] - number) - abs(a[*q] - number);
}
int main()
{
int i, j, n, k, flag , cost;
while(scanf("%d%d", &n, &k) == 2)
{
scanf("%s", str);
for(i = 0; i < n; i ++)
a[i] = str[i] - '0';
cost = 1000000000;
for(i = 0; i < 10; i ++)
{
for(j = 0; j < n; j ++)
r[j] = j;
number = i;
qsort(r, n, sizeof(r[0]), cmp);
sum[i] = 0;
int ok = 0,num = 0;
for(j = 0; j < n; j ++)
{
if(num == k)
ok = 1;
if(!ok)
{
b[i][r[j]] = i;
sum[i] += abs(number - a[r[j]]);
num ++;
}
else
b[i][r[j]] = a[r[j]];
}
if(sum[i] < cost)
{
cost = sum[i];
flag = i;
}
else if(sum[i] == cost)
{
int t = 0;
for(j = 0; j < n; j ++)
if(b[i][j] != b[flag][j])
{
if(b[i][j] < b[flag][j])
t = 1;
break;
}
if(t)
{
cost = sum[i];
flag = i;
}
}
}
printf("%d\n", cost);
for(i = 0; i < n; i ++)
printf("%d", b[flag][i]);
printf("\n");
}
return 0;
}