题目链接：http://acm.sgu.ru/problem.php?contest=0&problem=546
这题还好，１Ｙ，考虑情况周全，就没问题了，还好提交之前把想到的情况都测试了一遍．．
1 #include <iostream> 2 #include <cstdio> 3 #include <cstdlib> 4 #include <cstring> 5 #include <algorithm> 6 char s[202]; 7 int n, a, b, a0[202], b0[202]; 8 int main(void) { 9 //freopen("in.txt", "r", stdin); 10 while (~scanf("%d%d%d%s", &n, &a, &b, s)) { 11 int a1 = 0, b1 = 0; 12 for (int i = 0;i < n; ++i) { 13 if (s[i] == '0') a0[a1] = i, a1++; else if (s[i] == '1') b0[b1] = i, b1++; 14 } 15 if (a1 == a && b1 == b) printf("0 %s ", s); 16 else if (a+b>n) printf("-1 "); 17 else { 18 int cnt = 0, a2 = 0, b2 = 0; 19 a2 = a1-a, b2 = b1-b; 20 if (a1 < a) { 21 for (int f = 0; f < b2 && a1 < a; ++f) s[b0[f]] = '0', cnt++, a1++, b1--; 22 if (a1 < a) { 23 for (int e = 0; e < n && a1 < a; ++e) if (s[e] == '2') s[e] = '0', cnt++, a1++; 24 } 25 } 26 if (b1 < b) { 27 for (int f = 0; f < a2 && b1 < b; ++f) s[a0[f]] = '1', cnt++, b1++, a1--; 28 if (b1 < b) { 29 for (int e = 0; e < n && b1<b; ++e) if (s[e] == '2') s[e] = '1', cnt++, b1++; 30 } 31 } 32 if (a1 > a) { 33 for (int f = 0; f < n && a1 > a; ++f) if (s[f] == '0') a1--, s[f] = '2', cnt++; 34 } 35 if (b1 > b) { 36 for (int f = 0; f < n && b1 > b; ++f) if (s[f] == '1') b1--, s[f] = '2', cnt++; 37 } 38 printf("%d %s ", cnt, s); 39 } 40 } 41 42 return 0; 43 }
只是我的方法貌似比较笨＝＝