魔鬼PAT训练 DAY3
魔鬼PAT训练 DAY3
4.4.贪心
B1023. 组个最小数(20')
#include <iostream>
using namespace std;
int main() {
int num[10], i;
for(i = 0; i < 10; i++)
scanf("%d", num + i);
for(i = 1; i < 10; i++)
if(num[i]) break;
printf("%d", i);
num[i]--;
for(i = 0; i < 10; i++)
while(num[i]--) printf("%d", i);
return 0;
}
B2020/A10700.月饼(25')
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
struct mooncake {
double cnt, price;
};
vector<mooncake> v;
bool cmp(mooncake mc, mooncake mc2) {
return mc.price * mc2.cnt < mc2.price * mc.cnt;
}
int main() {
double N, target;
scanf("%lf %lf", &N, &target);
v.resize(N);
for(int i = 0; i < N; i++)
scanf("%lf", &v[i].price);
for(int i = 0; i < N; i++)
scanf("%lf", &v[i].cnt);
sort(v.begin(), v.end(), cmp);
double ans = 0;
for(int i = 0; i < N && target != 0; i++){
if(v[i].price <= target){
target -= v[i].price;
ans += v[i].cnt;
}else {
ans += (target * v[i].cnt / v[i].price);
target = 0;
}
}
printf("%.2f", ans);
return 0;
}
A1037.Magic Coupon(25')
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int N, M, a[999999], b[999999], ans = 0;
scanf("%d", &N);
for(int i = 0; i < N; i++) scanf("%d", a + i);
scanf("%d", &M);
for(int i = 0; i < M; i++) scanf("%d", b + i);
sort(a, a + N); sort(b, b + M);
for(int i = 0; i < min(N, M); i++)
if(a[i] < 0 && b[i] < 0) ans += a[i] * b[i];
for(int i = N - 1, j = M - 1; i >= 0 && j >= 0; i--, j--)
if(a[i] > 0 && b[j] > 0) ans += a[i] * b[j];
printf("%d", ans);
return 0;
}
A1067.Sort with Swap(0, i) (25')
#include <iostream>
#include <map>
#include <algorithm>
using namespace std;
map<int, int> m;
int N, cnt = 0, tmp;
int main() {
scanf("%d", &N);
for(int i = 0; i < N; i++){
scanf("%d", &tmp);
m[tmp] = i;
}
for(int i = 1; i < N; i++) {
if(i != m[i]) {
while(m[0] != 0) {
swap(m[0], m[m[0]]);
cnt++;
}
if(i != m[i]) {
swap(m[0], m[i]);
cnt++;
}
}
}
cout << cnt;
return 0;
}
A1038.Recover the Smallest Number(30')
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
bool cmp(string s1, string s2) {
return s1 + s2 < s2 + s1;
}
int main(){
int N;
cin >> N;
vector<string> v(N);
for(int i = 0; i < N; i++)
cin >> v[i];
sort(v.begin(), v.end(), cmp);
string res;
for(int i = 0; i < N; i++)
res += v[i];
while(res.length() != 0 && res[0] == '0')
res.erase(res.begin());
if(res.length() == 0) cout << 0;
else cout << res;
return 0;
}
4.5.二分
B1030/A1085.完美数列(25')
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main() {
int n;
long long p;
scanf("%d%lld", &n, &p);
vector<int> v(n);
for (int i = 0; i < n; i++)
cin >> v[i];
sort(v.begin(), v.end());
int result = 0, temp = 0;
for (int i = 0; i < n; i++) {
for (int j = i + result; j < n; j++) {
if (v[j] <= v[i] * p) {
temp = j - i + 1;
if (temp > result)
result = temp;
} else {
break;
}
}
}
cout << result;
return 0;
}
A1048.Find Coins
#include <iostream>
#include <map>
using namespace std;
int main() {
int N, M, tmp;
map<int, int> m;
scanf("%d%d", &N, &M);
while(N--) {
scanf("%d", &tmp);
m[tmp]++;
}
for(auto it = m.begin(); it != m.end(); it++) {
it->second--;
if(m[M - it->first]) {
printf("%d %d", it->first, M - it->first);
return 0;
}
}
printf("No Solution");
return 0;
}
B1040/A1093. 有几个PAT
#include <iostream>
using namespace std;
int main()
{
string s;
getline(cin,s);
long long P=0,A=0,T=0,sum=0;
for(int i=0;i<s.length();i++)
if(s[i]=='T') T++;
for(int i=0;i<s.length();i++){
if(s[i]=='P') P++;
if(s[i]=='T') T--;
if(s[i]=='A') sum+=((P%1000000007*T%1000000007)%1000000007);
}
cout<<sum%1000000007;
return 0;
}
B1045/A1101.快速排序
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(){
vector<int> res;
int N, Max = -1;
cin >> N;
int arr[N], cp[N];
for(int i = 0; i < N; i++) {
cin >> arr[i];
cp[i] = arr[i];
}
sort(cp, cp+N);
for(int i = 0; i < N; i++){
if(cp[i] == arr[i] && arr[i] > Max)
res.push_back(arr[i]);
if(arr[i] > Max) Max = arr[i];
}
printf("%d\n",res.size());
for(int i = 0; i < res.size(); i++)
if(i != res.size() - 1) printf("%d ", res[i]);
else printf("%d", res[i]);
printf("\n");
system("pause");
return 0;
}
5.1.简单数学
B1003.我要通过
#include <iostream>
using namespace std;
string str; int N;
int main() {
scanf("%d", &N);
while(N--) {
cin >> str;
int P = 0, T = 0, no = false;
while(str[P] != 'P' && P < str.length()) P++;
while(str[T] != 'T' && T < str.length()) T++;
if(P >= str.length() || T >= str.length() || T - P == 1) no = true;
for(int i = 0; i < str.length(); i++)
if(i != P && i != T && str[i] != 'A') no = true;
if(P * (T - P - 1) != (str.length() - T - 1)) no = true;
printf("%s\n", no ? "NO": "YES");
}
return 0;
}
A1069.数字黑洞
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int N;
scanf("%d", &N);
string str, rev;
do {
str = to_string(N);
while(str.length() != 4) str = "0" + str;
sort(str.begin(), str.end());
rev = str;
reverse(rev.begin(), rev.end());
N = stoi(rev) - stoi(str);
printf("%s - %s = %04d\n", rev.c_str(), str.c_str(), N);
}while(N != 0 && N != 6174);
return 0;
}
A1008.Elevator(0')
#include <iostream>
#include <map>
using namespace std;
int main() {
int N, level = 0, tmp, sum = 0;
scanf("%d", &N);
while(N--) {
scanf("%d", &tmp);
if(tmp > level) sum = sum + (tmp - level) * 6 + 5;
else sum = sum + (level - tmp) * 4 + 5;
level = tmp;
}
cout << sum;
return 0;
}
B1019/A1104.数列片段和(20')
#include <iostream>
using namespace std;
int main(){
int N; cin>>N;
double a[N],sum=0;
for(int i=0;i<N;i++) cin>>a[i];
for(int i=0;i<N;i++)
sum+=(a[i]*(i+1)*(N-i));
printf("%.2f",sum);
return 0;
}
A1049.Counting Ones(30')
