Is a "café" a "café", and are they the same length?

gistfile1.m

// $ clang -framework Foundation -o unicode-is-hard-lets-go-shopping unicode-is-hard-lets-go-shopping.m  && ./unicode-is-hard-lets-go-shopping 
// 2013-03-01 17:56:56.132 unicode-is-hard-lets-go-shopping[3390:707] string1='café', string2='café', string1.length=4, string2.length=5, [string1 isEqualToString:string2]=NO
// 2013-03-01 17:56:56.134 unicode-is-hard-lets-go-shopping[3390:707] precomposedString1='café', precomposedString2='café', precomposedString1.length=4, precomposedString2.length=4, [precomposedString1 isEqualToString:precomposedString2]=YES

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {
    @autoreleasepool {
      NSString *string1 = [NSString stringWithUTF8String:"\x63\x61\x66\xC3\xA9\x00"];
      NSString *string2 = [NSString stringWithUTF8String:"\x63\x61\x66\x65\xCC\x81\x00"];
      
      NSString *precomposedString1 = [string1 precomposedStringWithCanonicalMapping];
      NSString *precomposedString2 = [string2 precomposedStringWithCanonicalMapping];
      
      NSLog(@"string1='%@', string2='%@', string1.length=%ld, string2.length=%ld, [string1 isEqualToString:string2]=%@", string1, string2, string1.length, string2.length, [string1 isEqualToString:string2] ? @"YES" : @"NO");
      NSLog(@"precomposedString1='%@', precomposedString2='%@', precomposedString1.length=%ld, precomposedString2.length=%ld, [precomposedString1 isEqualToString:precomposedString2]=%@", precomposedString1, precomposedString2, precomposedString1.length, precomposedString2.length, [precomposedString1 isEqualToString:precomposedString2] ? @"YES" : @"NO");
    }
    return EXIT_SUCCESS;
}