为啥最近都没有arc啊...
A - Favorite Sound
#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <vector>
#include <queue>
#include <cmath>
#include <stack>
#include <deque>
#include <map>
#include <set>
#define ll long long
#define inf 0x3f3f3f3f
#define il inline
namespace io {
#define in(a) a = read()
#define out(a) write(a)
#define outn(a) out(a), putchar('\n')
#define I_int ll
inline I_int read() {
I_int x = 0, f = 1;
char c = getchar();
while (c < '0' || c > '9') {
if (c == '-') f = -1;
c = getchar();
}
while (c >= '0' && c <= '9') {
x = x * 10 + c - '0';
c = getchar();
}
return x * f;
}
char F[200];
inline void write(I_int x) {
if (x == 0) return (void) (putchar('0'));
I_int tmp = x > 0 ? x : -x;
if (x < 0) putchar('-');
int cnt = 0;
while (tmp > 0) {
F[cnt++] = tmp % 10 + '0';
tmp /= 10;
}
while (cnt > 0) putchar(F[--cnt]);
}
#undef I_int
}
using namespace io;
using namespace std;
#define N 100010
int a, b, c;
int main() {
in(a), in(b), in(c);
printf("%d\n", min(b / a, c));
}
B - K-th Common Divisor
显然,就是求gcd的第k小的因子。
#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <vector>
#include <queue>
#include <cmath>
#include <stack>
#include <deque>
#include <map>
#include <set>
#define ll long long
#define inf 0x3f3f3f3f
#define il inline
namespace io {
#define in(a) a = read()
#define out(a) write(a)
#define outn(a) out(a), putchar('\n')
#define I_int ll
inline I_int read() {
I_int x = 0, f = 1;
char c = getchar();
while (c < '0' || c > '9') {
if (c == '-') f = -1;
c = getchar();
}
while (c >= '0' && c <= '9') {
x = x * 10 + c - '0';
c = getchar();
}
return x * f;
}
char F[200];
inline void write(I_int x) {
if (x == 0) return (void) (putchar('0'));
I_int tmp = x > 0 ? x : -x;
if (x < 0) putchar('-');
int cnt = 0;
while (tmp > 0) {
F[cnt++] = tmp % 10 + '0';
tmp /= 10;
}
while (cnt > 0) putchar(F[--cnt]);
}
#undef I_int
}
using namespace io;
using namespace std;
#define N 100010
int a, b, k, d[N], tot;
int main() {
in(a), in(b), in(k);
int g = __gcd(a, b);
for(int i = 1; i * i <= g; ++i) {
if(g % i == 0) {
d[++tot] = i;
if(g / i != i) d[++tot] = g / i;
}
}
sort(d+1, d + tot + 1); reverse(d + 1, d + tot + 1);
printf("%d\n", d[k]);
}
C - Unification
栈的经典题。。。
#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <vector>
#include <queue>
#include <cmath>
#include <stack>
#include <deque>
#include <map>
#include <set>
#define ll long long
#define inf 0x3f3f3f3f
#define il inline
namespace io {
#define in(a) a = read()
#define out(a) write(a)
#define outn(a) out(a), putchar('\n')
#define I_int ll
inline I_int read() {
I_int x = 0, f = 1;
char c = getchar();
while (c < '0' || c > '9') {
if (c == '-') f = -1;
c = getchar();
}
while (c >= '0' && c <= '9') {
x = x * 10 + c - '0';
c = getchar();
}
return x * f;
}
char F[200];
inline void write(I_int x) {
if (x == 0) return (void) (putchar('0'));
I_int tmp = x > 0 ? x : -x;
if (x < 0) putchar('-');
int cnt = 0;
while (tmp > 0) {
F[cnt++] = tmp % 10 + '0';
tmp /= 10;
}
while (cnt > 0) putchar(F[--cnt]);
}
#undef I_int
}
using namespace io;
using namespace std;
#define N 100010
char s[N];
int n, st[N];
int main() {
scanf("%s", s + 1);
n = strlen(s + 1);
int ans = 0, top = 0;
for(int i = 1; i <= n; ++i) s[i] -= '0';
for(int i = 1; i <= n; ++i) {
if(top && s[top] ^ s[i]) {++ans, --top; continue;}
s[++top] = s[i];
}
printf("%d\n", ans * 2);
}
D - Decayed Bridges
正着计数太麻烦了。
考虑最后一条边断掉之后答案肯定是\(n(n-1)/2\)。
用个经典的套路,把删边弄成倒着连边。
那么每次多连一条边,联通的点数就多了\(siz_x*siz_y\)
用\(n(n-1)/2\)减去\(siz_x*siz_y\)即可。
注意longlong。
#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <vector>
#include <queue>
#include <cmath>
#include <stack>
#include <deque>
#include <map>
#include <set>
#define ll long long
#define inf 0x3f3f3f3f
#define il inline
namespace io {
#define in(a) a = read()
#define out(a) write(a)
#define outn(a) out(a), putchar('\n')
#define I_int ll
inline I_int read() {
I_int x = 0, f = 1;
char c = getchar();
while (c < '0' || c > '9') {
if (c == '-') f = -1;
c = getchar();
}
while (c >= '0' && c <= '9') {
x = x * 10 + c - '0';
c = getchar();
}
return x * f;
}
char F[200];
inline void write(I_int x) {
if (x == 0) return (void) (putchar('0'));
I_int tmp = x > 0 ? x : -x;
if (x < 0) putchar('-');
int cnt = 0;
while (tmp > 0) {
F[cnt++] = tmp % 10 + '0';
tmp /= 10;
}
while (cnt > 0) putchar(F[--cnt]);
}
#undef I_int
}
using namespace io;
using namespace std;
#define N 100010
int n, m;
int a[N], b[N], f[N];
ll siz[N];
ll ans = 0, sum = 0, res[N];
int find(int x) {
if(f[x] == x) return x;
else return f[x] = find(f[x]);
}
int main() {
in(n), in(m);
sum = (ll)(n * (n - 1ll) / 2ll);
for(int i = 1; i <= m; ++i) in(a[i]), in(b[i]);
for(int i = 1; i <= n; ++i) f[i] = i, siz[i] = 1ll;
for(int i = m; i; --i) {
res[i] = sum - ans;
int x = find(a[i]), y = find(b[i]);
if(x != y) {
ans += (ll)siz[x] * siz[y];
siz[x] += siz[y];
f[y] = x;
}
}
for(int i = 1; i <= m; ++i) printf("%lld\n", res[i]);
}
原文地址:https://www.cnblogs.com/henry-1202/p/10467882.html
时间: 2024-11-08 08:32:04