P5722 [深基4.例11] 数列求和

#include <cstdio>
int main()
{
    int n;
    scanf("%d", &n);
    int sum = 0;
    for (int i = 1; i <= n; i++) sum += i;
    printf("%d\n", sum);
    return 0;
}

P5718 [深基4.例2] 找最小值

#include <cstdio>
int main()
{
    int n;
    scanf("%d", &n);
    int mn = 1000;
    for (int i = 0; i < n; ++i) {
        int x;
        scanf("%d", &x);
        if (x < mn) mn = x;
    }
    printf("%d\n", mn);
    return 0;
}

P5724 [深基4.习5] 求极差 / 最大跨度值

#include <cstdio>
#include <algorithm>
using namespace std;
int main()
{
    int n;
    scanf("%d", &n);
    int mx = 0, mn = 1000;
    for (int i = 0; i < n; ++i) {
        int x;
        scanf("%d", &x);
        mx = max(mx, x);
        mn = min(mn, x);
    }
    printf("%d\n", mx - mn);
    return 0;
}

P1085 [NOIP2004 普及组] 不高兴的津津

#include <cstdio>
int main()
{
    int unhappy = 0;
    int day = 0;
    for (int i = 1; i <= 7; i++) {
        int a, b;
        scanf("%d%d", &a, &b);
        if (a + b > 8 && a + b > unhappy) {
            unhappy = a + b;
            day = i;
        }
    }
    printf("%d\n", day);
    return 0;
}

P5719 [深基4.例3] 分类平均

#include <cstdio>
int main()
{
    int n, k;
    scanf("%d%d", &n, &k);
    int sum1 = 0, cnt1 = 0;
    int sum2 = 0, cnt2 = 0;
    for (int i = 1; i <= n; ++i) {
        if (i % k == 0) {
            sum1 += i;
            ++cnt1;
        } else {
            sum2 += i;
            ++cnt2;
        }
    }
    printf("%.1f %.1f\n", sum1 * 1.0 / cnt1, sum2 * 1.0 / cnt2);
    return 0;
}

P1075 [NOIP2012 普及组] 质因数分解

#include <cstdio>
int main()
{
    int n;
    scanf("%d", &n);
    for (int i = 2; i * i <= n; ++i)
        if (n % i == 0) {
            printf("%d\n", n / i);
            break;
        }
    return 0;
}

P5720 [深基4.例4] 一尺之棰

#include <cstdio>
int main()
{
    int a;
    scanf("%d", &a);
    int cur = 1;
    while (a > 1) {
        a /= 2;
        ++cur;
    }
    printf("%d\n", cur);
    return 0;
}

P1035 [NOIP2002 普及组] 级数求和

#include <cstdio>
int main()
{
    int k;
    scanf("%d", &k);
    double s = 0;
    int n = 0;
    while (s <= k) {
        n++;
        s += 1.0 / n;
    }
    printf("%d\n", n);
    return 0;
}

P2669 [NOIP2015 普及组] 金币

#include <cstdio>
int main()
{
    int k;
    scanf("%d", &k);
    int sum = 0;
    int coin = 1;
    int day = 0;
    for (int i = 1; i <= k; i++) {
        sum += coin;
        day++;
        if (day == coin) {
            coin++;
            day = 0;
        }
    }
    printf("%d\n", sum);
    return 0;
}

P1307 [NOIP2011 普及组] 数字反转

#include <cstdio>
int main()
{
    int n;
    scanf("%d", &n);
    if (n < 0) {
        printf("-");
        n = -n;
    }
    int ans = 0;
    while (n > 0) {
        ans = ans * 10 + n % 10;
        n /= 10;
    }
    printf("%d\n", ans);
    return 0;
}

P5721 [深基4.例6] 数字直角三角形

#include <cstdio>
int main()
{
    int n;
    scanf("%d", &n);
    int num = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n - i + 1; j++) {
            num++;
            printf("%02d", num);
        }
        printf("\n");
    }
    return 0;
}

P5725 [深基4.习8] 求三角形

#include <cstdio>
int main()
{
    int n;
    scanf("%d", &n);
    int num = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            num++;
            printf("%02d", num);
        }
        printf("\n");
    }
    printf("\n");
    num = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n - i; j++) printf("  ");
        for (int j = 1; j <= i; j++) {
            num++;
            printf("%02d", num);
        }
        printf("\n");
    }
}

P1980 [NOIP2013 普及组] 计数问题

#include <cstdio>
int main()
{
    int n, x;
    scanf("%d%d", &n, &x);
    int ans = 0;
    for (int i = 1; i <= n; i++) {
        int t = i;
        while (t > 0) {
            if (t % 10 == x) ans++;
            t /= 10;
        }
    }
    printf("%d\n", ans);
    return 0;
}

P4956 [COCI2017-2018#6] Davor

#include <cstdio>
int main()
{
    int n;
    scanf("%d", &n);
    n = n / 52 / 7;
    for (int x = 100; x >= 1; x--) {
        if ((n - x) % 3 == 0) {
            int k = (n - x) / 3;
            if (k > 0) {
                printf("%d\n%d\n", x, k);
                break;
            }
        }
    }
    return 0;
}

P1888 三角函数

#include <cstdio>
#include <algorithm>
using namespace std;
int main()
{
    int a, b, c;
    scanf("%d%d%d", &a, &b, &c);
    int big = max(a, max(b, c));
    int small = min(a, min(b, c));
    int x = big, y = small;
    while (y != 0) {
        int t = x;
        x = y;
        y = t % y;
    }
    big /= x;
    small /= x;
    printf("%d/%d\n", small, big);
    return 0;
}

P1420 最长连号

#include <cstdio>
int main()
{
    int n;
    scanf("%d", &n);
    int pre = -1, ans = 1, len = 1;
    for (int i = 0; i < n; ++i) {
        int x;
        scanf("%d", &x);
        if (pre + 1 == x) {
            len++;
            if (len > ans) ans = len;
        } else {
            len = 1;
        }
        pre = x;
    }
    printf("%d\n", ans);
    return 0;
}

P5726 [深基4.例9] 打分

#include <cstdio>
#include <algorithm>
using namespace std;
int main()
{
    int n;
    scanf("%d", &n);
    int sum = 0;
    int mx = 0;
    int mn = 10;
    for (int i = 0; i < n; ++i) {
        int x;
        scanf("%d", &x);
        sum += x;
        mx = max(mx, x);
        mn = min(mn, x);
    }
    printf("%.2f\n", 1.0 * (sum - mx - mn) / (n - 2));
    return 0;
}