（学生成绩）n = int(input())stu = []for i in range(n): inp = list(input().split()) stu.append(dict(num=inp[0],name=inp[1],merit=inp[2]))m = input().strip()t = Truefor i in range(n): if stu[i]['num'] == m: print(stu[i]['num'],stu[i]['name'],stu[i]['merit']) t = Falseif t: print('Not Found!')（对称矩阵）n = int(input())a = [[0 for j in range(n)] for i in range(n)]for i in range(n): for j in range(n): a[i][j] = str(abs(j-i))for i in range(n): print(' '.join(a[i]))（两军交锋）t = int(input())for i in range(t): u,v,w,l = list(map(float,input().split())) print('%.3f'%((l*w)/(u+v)))（砍树）m, n = list(map(int, input().split()))a = [i+1 for i in range(m)]b = []i = 0while True: if a[i % m] in b: break else: b.append(a[i % m]) i += (n+1)print(len(b))