1.
#include <iostream>
using namespace std;
int main() {
int a[6] = {1, 2, 3, 4, 5, 6};
int pi = 0;
int pj = 5;
int t , i;
while (pi < pj) {
t = a[pi];
a[pi] = a[pj];
a[pj] = t;
pi++;
pj--;
}
for (i = 0; i < 6; i++)
cout << a[i] << ",";
cout << endl;
return 0;
}
输出：6,5,4,3,2,1,
2.
#include <iostream>
using namespace std;
int main() {
char a[100][100], b[100][100];
string c[100];
string tmp;
int n, i = 0, j = 0, k = 0, total_len[100], length[100][3];
cin >> n;
getline(cin, tmp);
for (i = 0; i < n; i++) {
getline(cin, c[i]);
total_len[i] = c[i].size();
}
for (i = 0; i < n; i++) {
j = 0;
while (c[i][j] != ':') {
a[i][k] = c[i][j];
k = k + 1;
j++;
}
length[i][1] = k - 1;
a[i][k] = 0;
k = 0;
for (j = j + 1; j < total_len[i]; j++) {
b[i][k] = c[i][j];
k = k + 1;
}
length[i][2] = k - 1;
b[i][k] = 0;
k = 0;
}
for (i = 0; i < n; i++) {
if (length[i][1] >= length[i][2])
cout << "NO,";
else {
k = 0;
for (j = 0; j < length[i][2]; j++) {
if (a[i][k] == b[i][j])
k = k + 1;
if (k > length[i][1])
break; }
if (j == length[i][2])
cout << "NO,";
else
cout << "YES,";
}
}
cout << endl;
return 0;
}
输入：3
AB:ACDEbFBkBD
AR:ACDBrT
SARS:Severe Atypical Respiratory Syndrome
（注：输入各行前后均无空格）
输出：YES,NO,YES,
3.
#include <iostream>
using namespace std;
int lps(string seq, int i, int j) {
int len1, len2;
if (i == j)
return 1;
if (i > j)
return 0;
if (seq[i] == seq[j])
return lps(seq, i + 1, j - 1) + 2;
len1 = lps(seq, i, j - 1);
len2 = lps(seq, i + 1, j);
if (len1 > len2)
return len1;
return len2;
}
int main() {
string seq = "acmerandacm";
int n = seq.size();
cout << lps(seq, 0, n - 1) << endl;
return 0;
}
输出：5
4.
#include <iostream>
#include <cstring>
using namespace std;
int map[100][100];
int sum[100], weight[100];
int visit[100];
int n;
void dfs(int node) {
visit[node] = 1;
sum[node] = 1;
int v, maxw = 0;
for (v = 1; v <= n; v++) {
if (!map[node][v] || visit[v])
continue;
dfs(v);
sum[node] += sum[v];
if (sum[v] > maxw)
maxw = sum[v];
}
if (n - sum[node] > maxw)
maxw = n - sum[node];
weight[node] = maxw;
}
int main() {
memset(map, 0, sizeof(map));
memset(sum, 0, sizeof(sum));
memset(weight, 0, sizeof(weight));
memset(visit, 0, sizeof(visit));
cin >> n;
int i, x, y;
for (i = 1; i < n; i++) {
cin >> x >> y;
map[x][y] = 1;
map[y][x] = 1;
}
dfs(1);
int ans = n, ansN = 0;
for (i = 1; i <= n; i++)
if (weight[i] < ans) {
ans = weight[i];
ansN = i;
}
cout << ansN << " " << ans << endl;
return 0;
}
输入：
11
1 2
1 3
2 4
2 5
2 6
3 7
7 8
7 11
6 9
9 10
输出：2 5