P1428 小鱼比可爱

image-20240428213943899

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#include <iostream>
const int N = 105;
int a[N];
using namespace std;
int main()
{
int n;
cin >> n;
for (int i = 0; i < n; i++)
cin >> a[i];
for (int i = 0; i < n; i++)
{
int count = 0;
for (int j = 0; j < i; j++)
{
if (a[i] > a[j])
count++;
}
cout << count << " ";
}
}

P1427 小鱼的数字游戏

image-20240428230234332

看到的优秀题解,方便你快速过一遍知识:一个红题带你了解绿(黄)题知识点 - 洛谷专栏 (luogu.com.cn)

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#include <iostream>
#include <stack>
using namespace std;
const int N = 105;
int a[N];
stack<int> st;
int main()
{
int tmp;
while (1)
{
cin >> tmp;
if (tmp == 0)
break;
st.push(tmp);
}
while (!st.empty())
{
cout << st.top() << " ";
st.pop();
}
}

P5727 【深基5.例3】冰雹猜想

image-20240514193755513

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#include <iostream>
#include <stack>
using namespace std;
const int N = 10005;
int a[N];
stack<int> st;
int main()
{
int n;
cin >> n;
st.push(n);
while (n != 1)
{
if (n % 2 == 0)
{
n = n / 2;
}
else
{
n = n * 3 + 1;
}
st.push(n);
}
while (!st.empty())
{
cout << st.top() << " ";
st.pop();
}
}

P1047 [NOIP2005 普及组] 校门外的树

image-20240429175906480

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#include <iostream>

using namespace std;
const int N = 100005;
int a[N];

int main()
{
int n, m;
cin >> n >> m;
n += 1;
int l, r;
for (int i = 0; i < m; i++)
{
cin >> l >> r;
for (int j = l; j <= r; j++)
a[j] = 1;
}
int count=0;
for (int i = 0; i < n; i++)
{
if (a[i] == 0)
count++;

}
cout << count ;
}

P5728 【深基5.例5】旗鼓相当的对手

image-20240429182951046

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#include <iostream>
#include <algorithm>
using namespace std;
const int N = 1005;
int a[N][3];

int main()
{
int n, count = 0;
cin >> n;
for (int i = 0; i < n; i++)
{
cin >> a[i][0] >> a[i][1] >> a[i][2];
}
for (int i = 0; i < n; i++)
{
for (int j = i+1; j < n; j++) //注意+1,不然比较的是自己,会多n次
{
if (abs(a[i][0] - a[j][0]) <= 5 && abs(a[i][1] - a[j][1]) <= 5 &&
abs(a[i][2] - a[j][2]) <= 5 && abs(a[i][0] + a[i][1] + a[i][2] - a[j][0] - a[j][1] - a[j][2]) <= 10) //绝对值小于
count++;
}
}

cout << count;

}

P5729 【深基5.例7】工艺品制作

image-20240429195454137

这题要注意x,y,z的范围。这里我采用边挖方块边计算的方法,可以省下一次三重循环遍历数组:

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#include <iostream>
#include <algorithm>
using namespace std;
const int N = 25;
int a[N][N][N];

int main()
{
int w, x, h;
cin >> w >> x >> h;
int q;
cin >> q;

int x1, y1, z1;
int x2, y2, z2;
int count = 0;
for (int i = 0; i < q; i++)
{
cin >> x1 >> y1 >> z1;
cin >> x2 >> y2 >> z2;
for (int j = x1; j <= x2; j++)
{
for (int k = y1; k <= y2; k++)
{
for (int l = z1; l <= z2; l++)
{

if (a[j][k][l] == 0)
{
count++;
a[j][k][l] = -1;
}

}
}
}
}
/*
若两坐标点的位置大小不确定,还需要
for (int j = min(x1,x2); j <= max(x1,x2); j++)
for (int k = min(y1,y2); k <= max(y1,y2); k++)
for (int l = min(z1,z2); l <= (z1,z2); l++)

*/

cout << w*x*h-count;

}

P2550 [AHOI2001] 彩票摇奖

image-20240429202113371

我们可以将能数组中中奖的号码的数字在数组的位置设置为1,这样只需要对每个彩票号码取数组下标即可判断是否中奖。

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#include <iostream>
#include <algorithm>
using namespace std;
const int N = 35;
int a[N];
int b[10]; //中奖次数数组

int main()
{
int n;
cin >> n;
for (int i = 1; i <= 7; i++)
{
int tmp;
cin >> tmp;
a[tmp] = 1;
}
for (int i = 0; i < n; i++)
{
int count = 0;
int tmp;
for (int i = 1; i <= 7; i++)
{
cin >> tmp;
if (a[tmp] == 1)
count++;
}
b[count]++;
}
for (int i = 7; i >=1 ; i--)
{
cout << b[i] << " ";
}

}

P2615 [NOIP2015 提高组] 神奇的幻方

image-20240429221324882

做的有点麻,经典行列分不清,然后还自作聪明把条件合并。下次要细心,把行列分清QwQ。这题的话,看题写判断就OK了。

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#include <iostream>
#include <algorithm>
using namespace std;
const int N = 45;
int a[N][N];
int main()
{
int n;
cin >> n;

int raw = 1, col = n/2 + 1; //表示k-1数字的位置,初始化为1的位置·
a[raw][col] = 1;
for (int i = 2; i <= n*n; i++)
{
if (raw == 1 && col != n )
{
raw = n ;
col = col + 1;
a[raw][col] = i;

}
else if (raw != 1 && col==n )
{
raw = raw - 1;
col = 1;
a[raw][col] = i;

}
else if(raw == 1 && col == n)
{
raw = raw + 1;
col = col ;
a[raw][col] = i;

}
else
{
if (a[raw - 1][col + 1] == 0) //右上
{
raw = raw - 1;
col = col + 1;
a[raw][col] = i;

}
else
{
raw = raw + 1;
col = col ;
a[raw][col] = i;
}
}

}
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= n; j++)
{
cout << a[i][j] << " ";
}
cout << endl;
}

}

在题解中,有一种新的方案题解 P2615 【神奇的幻方】 - 洛谷专栏 (luogu.com.cn),可以总结一下从第一行中点开始,把每一个下面的数放到“右上角”,若右上角有数,则放到正下方。当i=2时,1的右上方为2(取余),当i=3时 ,2的右上方为3(取余),当i=4时,3的右上方已经被1占用,因此放入下方。

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8 1 6
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4 9 2
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#include <iostream>
#include <algorithm>
using namespace std;
const int N = 45;
int a[N][N];

int main()
{
int n;
cin >> n;
int raw = 1, col = n/2 + 1;

for (int i = 1; i <= n*n; i++)
{
a[raw][col] = i;
if (a[(raw - 2 + n) % n + 1][col % n + 1] == 0) //要避免数组下标取0
raw = (raw - 2 + n) % n + 1, col = col % n + 1;
else
raw = raw % n + 1;
}
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= n; j++)
{
cout << a[i][j] << " ";
}
cout << endl;
}

}

P5730 【深基5.例10】显示屏

image-20240514193936527

打表仙人(bushi),我们每四列输出一个字母,先把.所在下标赋值,最后为未初始化的下标赋X,对于最后一列不能有.的问题,我们直接不输出即可:

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#include <iostream>
#include <algorithm>
using namespace std;
const int N = 1035;
char a[5][N];


int main()
{
int n;
cin >> n;
int col = 0; //表示该数字开始的列
for(int i = 0;i < n;i++)
{
char tmp;
cin >> tmp;

if (tmp == '0')
a[1][col + 1] = '.', a[2][col + 1] = '.', a[3][col + 1] = '.',
a[0][col + 3] = '.', a[1][col + 3] = '.', a[2][col + 3] = '.', a[3][col + 3] = '.', a[4][col + 3] = '.';
if (tmp == '1')
a[0][col] = '.', a[1][col] = '.', a[2][col] = '.', a[3][col] = '.', a[4][col] = '.',
a[0][col + 1] = '.', a[1][col + 1] = '.', a[2][col + 1] = '.', a[3][col + 1] = '.', a[4][col + 1] = '.',
a[0][col + 3] = '.', a[1][col + 3] = '.', a[2][col + 3] = '.', a[3][col + 3] = '.', a[4][col + 3] = '.';
if (tmp == '2')
a[1][col] = '.', a[1][col + 1] = '.', a[3][col + 1] = '.', a[3][col + 2] = '.',
a[0][col + 3] = '.', a[1][col + 3] = '.', a[2][col + 3] = '.', a[3][col + 3] = '.', a[4][col + 3] = '.';
if (tmp == '3')
a[1][col] = '.', a[1][col + 1] = '.', a[3][col] = '.', a[3][col + 1] = '.',
a[0][col + 3] = '.', a[1][col + 3] = '.', a[2][col + 3] = '.', a[3][col + 3] = '.', a[4][col + 3] = '.';
if (tmp == '4')
a[3][col] = '.', a[3][col + 1] = '.', a[4][col] = '.', a[4][col + 1] = '.', a[0][col+1] = '.', a[1][col + 1] = '.',
a[0][col + 3] = '.', a[1][col + 3] = '.', a[2][col + 3] = '.', a[3][col + 3] = '.', a[4][col + 3] = '.';
if (tmp == '5')
a[1][col + 1] = '.', a[1][col + 2] = '.', a[3][col] = '.', a[3][col + 1] = '.',
a[0][col + 3] = '.', a[1][col + 3] = '.', a[2][col + 3] = '.', a[3][col + 3] = '.', a[4][col + 3] = '.';
if (tmp == '6')
a[1][col + 1] = '.', a[1][col + 2] = '.', a[3][col + 1] = '.',
a[0][col + 3] = '.', a[1][col + 3] = '.', a[2][col + 3] = '.', a[3][col + 3] = '.', a[4][col + 3] = '.';
if (tmp == '7')
a[1][col] = '.', a[2][col] = '.', a[3][col] = '.', a[4][col] = '.',
a[1][col + 1] = '.', a[2][col + 1] = '.', a[3][col + 1] = '.', a[4][col + 1] = '.',
a[0][col + 3] = '.', a[1][col + 3] = '.', a[2][col + 3] = '.', a[3][col + 3] = '.', a[4][col + 3] = '.';
if (tmp == '8')
a[1][col + 1] = '.', a[3][col + 1] = '.',
a[0][col + 3] = '.', a[1][col + 3] = '.', a[2][col + 3] = '.', a[3][col + 3] = '.', a[4][col + 3] = '.';
if (tmp == '9')
a[1][col + 1] = '.', a[3][col + 1] = '.', a[3][col] = '.',
a[0][col + 3] = '.', a[1][col + 3] = '.', a[2][col + 3] = '.', a[3][col + 3] = '.', a[4][col + 3] = '.';
col += 4;
}


for (int i = 0; i < 5; i++)
{
for (int j = 0; j < n * 4 - 1; j++)
{

if (a[i][j] == 0)
a[i][j] = 'X';
cout << a[i][j];
}
cout << endl;
}
}

也是看了一下题解题解 P5730 【【深基5.例10】显示屏】 - 洛谷专栏 (luogu.com.cn),感觉这种方法是最优解,能够拥有最快的打表速度。

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string ans[10];
if(a[i]=='1')
{
ans[1]+="..X.";
ans[2]+="..X.";
ans[3]+="..X.";
ans[4]+="..X.";
ans[5]+="..X.";
}
//最后输出也是把最后的.截取掉

#

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#include <iostream>
using namespace std;
const int N = 15;
int a[N];

int main()
{
int l, r;
cin >> l >> r;
for (int i = l; i <= r; i++)
{
int tmp = i;
while (tmp != 0)
{
a[tmp % 10]++;
tmp /= 10;
}
}
for (int i = 0; i < 10; i++)
{
cout << a[i] << " ";
}
}

P5731 【深基5.习6】蛇形方阵

image-20240514194147792

把最后一次填空交给下一循环

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#include <iostream>
using namespace std;
const int N = 15;
int arr[N][N];

int main()
{
int n;
cin >> n;
int x = 1, y = 0, z = 1;
while (z <= n * n)
{
while (y < n && !arr[x][y+1]) {
y++;
arr[x][y] = z;
z++;
}
while (x < n && !arr[x+1][y]) {
x++;
arr[x][y] = z;
z++;
}
while (y >1 && !arr[x][y-1]) {
y--;
arr[x][y] = z;
z++;
}
while (x > 1 && !arr[x-1][y]) {
x--;
arr[x][y] = z;
z++;
}
}
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= n; j++) printf("%3d", arr[i][j]);
printf("\n");
}
}

P2141 [NOIP2014 普及组] 珠心算测验

image-20240514203336359

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#include <iostream>
using namespace std;
const int N = 20005;
bool a[N];
int b[105];

int main()
{
int n;
cin >> n;
int count = 0;
for (int i = 0; i < n; i++)
{
cin >> b[i];
}
for (int i = 0; i < n; i++)
{
for (int j = i + 1; j < n; j++)
{
a[b[i] + b[j]] = true;
}
}
for (int i = 0; i < n; i++)
{
if (a[b[i]] == true)
{
count++;
}
}
cout << count << endl;
}

P1161 开灯

image-20240514194446149

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#include <iostream>
#include<cmath>
using namespace std;


int main()
{
int n;
cin >> n;
double a;
int b;
int ans = 0;
while (n--)
{
cin >> a >> b;
for (int i = 1; i <= b; i++)
{
ans ^= (int)floor(a * i);
}

}

cout << ans;
}

P5732 【深基5.习7】杨辉三角

image-20240514202236754

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#include <iostream>

using namespace std;
const int N = 25;
int arr[N][N];

int main()
{
int n;
cin >> n;
arr[0][0] = 1;
for (int i = 1; i < n; i++)
{
arr[i][i] = 1;
}
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= i; j++)
{
arr[i][j] = arr[i - 1 ][j] + arr[i - 1][j - 1];
}

}


for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= i; j++)
{
cout << arr[i][j] << " ";
}
cout << endl;
}
}

P1789 【Mc生存】插火把

image-20240514202052617

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#include <iostream>
using namespace std;
const int N = 105;
int arr[N][N];

int main() {
int Count = 0;
int num;
cin >> num;
int a, b;
cin >> a >> b;
while (a--) {
int x, y;
cin >> x >> y;
arr[x][y] = 1;
for (int i = -1; i < 2; i++)
for (int j = -1; j < 2; j++) {
if (x + i >= 0 && y + j >= 0)
arr[x + i][y + j] = 1;
}
arr[x + 2][y] = 1;
arr[x][y + 2] = 1;

if (x - 2 >= 0)
arr[x - 2][y] = 1;
if (y - 2 >= 0)
arr[x][y - 2] = 1;
}
while (b--) {
int x, y;
cin >> x >> y;
for (int i = -2; i < 3; i++) {
for (int j = -2; j < 3; j++) {
if (x + i >= 0 && y + j >= 0)
arr[x + i][y + j] = 1;
}
}
}

for (int i = 1; i <= num; i++) {
for (int j = 1; j <= num; j++) {
if (arr[i][j] == 0)
Count++;
}
}
cout << Count;
}

压缩技术

image-20240514201704482

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#include <iostream>
#include <assert.h>
using namespace std;
const int N =205;
int arr[N][N];

int main()
{

int num;
cin >> num;
int sum = num * num;
int count = 0;
int raw = 0, col = 0;
while (count < sum)
{
int a, b;
cin >> a >> b;
count += a + b;

while(a--)
{
arr[raw][col] = 0;
col++;
if (col == num )
{
col = 0;
raw++;
}
}

while(b--)
{
arr[raw][col] = 1;
col++;
if (col == num)
{
col = 0;
raw++;
}
}
}
for (int i = 0; i < num; i++)
{

for (int j = 0; j < num; j++)
cout << arr[i][j] ;
cout << endl;
}

return 0;
}

压缩技术[续集版]

image-20240514201732185

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#include <iostream>
#include<cmath>
using namespace std;
const int N =40005;
int arr[N];

int main()
{


int total = 0, count = 0;

char tmp;
char flag = '0'; //注意赋值为字符而不是
int i = 0;
while (cin >> tmp)
{
total++;
if (tmp == flag)
count++;
else
{
arr[i++] = count;
flag = tmp;
count = 1;
}
}

cout << sqrt(total) << " ";

for(int j =0; j < i; j++)
{
cout << arr[j] << " ";

}
cout << count;

return 0;
}

P1205 [USACO1.2] 方块转换 Transformations

转180度即转两次90度,转270次即转三次90度,我们可以通过90度旋转函数调用来实现图片旋转。

旋转矩阵我们可以通过先转置矩阵,然后再将第i行与n-i行进行交换,得到顺时针旋转90度的矩阵。

image-20240514203408143

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#include<iostream>
using namespace std;

const int N = 15;
char matrix[N][N];
char matrixcopy[N][N];
char matrix2[N][N];

int n;

// 转置矩阵
void transpose() {
for (int i = 0; i < n; i++) {
for (int j = i + 1; j < n; j++) {
swap(matrix[i][j], matrix[j][i]);
}
}
}

// 水平翻转
void reverseRows() {
for (int i = 0; i < n; i++) {
for (int j = 0; j < n / 2; j++) {
swap(matrix[i][j], matrix[i][n - j - 1]);
}
}
}

// 顺时针旋转矩阵
void rotateClockwise() {
transpose();
reverseRows();
}

// 判断结果
bool JudgeRes() {
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (matrix[i][j] != matrix2[i][j]) {
return false;
}
}
}
return true;
}

// 初始化矩阵
void Init() {
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
matrix[i][j] = matrixcopy[i][j];
}
}
}

// 检查旋转一次是否匹配
bool res1() {
rotateClockwise();
if (JudgeRes()) return true;
return false;
}

// 检查旋转两次是否匹配
bool res2() {
rotateClockwise();
if (JudgeRes()) return true;
return false;
}

// 检查旋转三次是否匹配
bool res3() {
rotateClockwise();
if (JudgeRes()) return true;
return false;
}

// 检查水平翻转是否匹配
bool res4() {
Init();
reverseRows();
if (JudgeRes()) return true;
return false;
}

// 检查旋转后水平翻转是否匹配
bool res5() {
bool flag;
res1();
if (JudgeRes()) return true;
res2();
if (JudgeRes()) return true;
res3();
if (JudgeRes()) return true;
return false;
}

// 检查原始矩阵是否匹配
bool res6() {
Init();
if (JudgeRes()) return true;
return false;
}

// 无操作,总是返回真
bool res7() {
return true;
}

// 判断函数
void judge() {
if (res1()) { cout << 1 << endl; return; }
if (res2()) { cout << 2 << endl; return; }
if (res3()) { cout << 3 << endl; return; }
if (res4()) { cout << 4 << endl; return; }
if (res5()) { cout << 5 << endl; return; }
if (res6()) { cout << 6 << endl; return; }
if (res7()) { cout << 7 << endl; return; }
}

int main() {
cin >> n;
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
cin >> matrix[i][j];
}
}
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
matrixcopy[i][j] = matrix[i][j];
}
}
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
cin >> matrix2[i][j];
}
}
judge();
return 0;
}