Codeforces Round 427 B The name on the board 水题
题目链接: http://codeforces.com/contest/835/problem/B
题目描述: 一个数原来的和至少K,再给出一个数问最少改变几位可以得到原来那个数
解题思路: 水题
代码:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#include <iostream> #include <cstdio> #include <string> #include <vector> #include <cstring> #include <iterator> #include <cmath> #include <algorithm> #include <stack> #include <deque> #include <map> #define lson l, m, rt<<1 #define rson m+1, r, rt<<1|1 #define mem0(a) memset(a,0,sizeof(a)) #define meminf(a) memset(a,0x3f,sizeof(a)) using namespace std; const int maxn = 1e6 + 100; char a[maxn]; int s[maxn]; int main() { memset(s, 0, sizeof(s)); int k; scanf( "%d%s", &k, a ); int len = (int)strlen(a); for( int i = 0; i < len; i++ ) { s[i] = (int)a[i]-48; } // for( int i = 0; i <len; i++ ) { // cout << s[i] << endl; // } int sum = 0; for( int i = 0; i < len; i++ ) { sum += s[i]; // cout << s[i] << endl; } // cout << sum << endl; if( sum >= k ) { printf( "0\n" ); return 0; } else { sort(s, s+len); int ans = 0; while( sum < k ) { // cout << sum << endl; sum += (9-s[ans]); ans++; } cout << ans << endl; } return 0; }
思考: 一道水题, 不应该写到博客上的......算了都写这么多了, 以后不写这种题了
posted on 2017-08-14 11:27 FriskyPuppy 阅读(134) 评论(0) 编辑 收藏 举报